P

PAH BUAY SI (pah bway see)
Hokkien phrase meaning “indestructible” or “invincible”. Literally: “beat but won’t die”.
“That bloody cockroach! Pa buay si one!” 

PAH CHIAO
A Hokkien term which literally translates as “beat bird”. It either describes someone with a squint or being ‘cockeyed’, or is used to scold someone for inability to see properly. One wonders whether the term was derived from an activity that is often said to cause its practitioners to go blind.
1.  “Why is Kate Moss so popular? She’s a bit pah chiao one.”
2.  “The statue is so bleddy big, why  you cannot see? You pah chiao, is it?” 

PAH LAN (contributed by jianhui)
Nothing to do with genitalia whatsoever, it means to play Local Area Network (LAN) games.  However, considering that "Pah" is Hokkien for "hit", there is clearly a slight obscene connotation.
"Wah piang eh, that cybercafe at Orchard damn cheap, ah... Tomorrow, we go there and pah LAN, okay?

PAI KIA (pah-ee kee-ah) (contributed by akm)
Hokkien phrase which literally means "bad kid" or "bad boy".  Describes a young ruffian.
"You go and mix with all those pai kia, one day sure kena sai." (If you continue fraternizing with ruffians, you will surely get into trouble.")

PAI SEH (pah-ee say)
Hokkien for “shy” or “to have a sense of shame”. Can be used to express humility or embarrassment.
1.  “When it comes to asking favours, Ah Beng is damn buay pai seh one.” (Johnny has no qualms about asking for favours.)
2.  “This is the third time I’m borrowing money from you. Damn pai seh, man.”

PAIN
In true Singlish economy, "painful"
"Ow! Why you step on my foot? Damn pain, you know!"

PAK CHEW CHENG
Literally, to hit the hand gun.  The Hokkien euphemism for masturbation.  The Mandarin corollary is "da shou qiang".

PAK KIU (contributed by selena and conrad)
Hokkien phrase literally meaning " hit ball". Used in all sports involving a ball, from soccer to snooker. 
"Eh, tonight you wanna go to Kim Seng to pak kiu or not?"

PAK TOR
Hokkien for “going on a date”.
“Eh, hurry up leh! I got to go pak tor with my char bor.”

PAKAT
Malay for "to conspire" or to gang up against.
"Now all the high-tech companies want to pakat against Microsoft."   

PAKAY/BOH PAKAY/NO PAKAI/TAK PAKAI (pah-kay) (contributed by edaniel)
Derived from the Malay word "pakai" which means to wear (clothes), or to use or apply.  Somehow, it's morphed to mean "genuine" or "true", but usually in its negation, such that "boh pakay" is the Singlish equivalent of "inapplicable" or "unusable" or "ersatz".
1. "This Lolex watch boh pakay one, made in China!"
2. Ah Beng: "My joker got pakay or not?"
    Ah Seng: "Wah lu, you got play cards before or not? Since when joker got pakay? Joker boh pakay, lah!"

PAKTOLOGY
The study and practice of “Pak Tor”. 
“You so fast got another girlfriend? You studying for Ph.D. in paktology is it?”
See: Pak Tor

PALALALOGRAM (contributed by J.T.)
The typical Singaporean Chinese-educated English Maths  teacher's/lecturer's  pronunciation of 'parallelogram'. Most commonly heard in mathematics  classes in Uni, JC, Poly and Sec School. Often heard among students 
too.
"Eh, how to find the area of this palalalogram, ha?"

PANG SEH/PANG SEH KING (contributed by revolushun and Neil Yang)
"Pang Seh" is a Hokkien term which literally means "To Abandon".  It is used to describe being stood up. A Pang Seh King is thus someone who habitually does not turn up for appointments.
1. "Wah lau, damn shy, man.  Ah Lian on her wedding day kena pang seh by her husband." 
2. "Wah lau, he damn pang seh king one, you still ask him to come for what?"

PAO BAK CHANG (contributed by Woogie)
Literally, Hokkien for "wrapping meat dumplings". Used to describe girls who lack flattering figures, but who insist on wearing figure-hugging clothes.
"Piang eh, Ah Lian so fat still want to wear like that - really pao bak chang only, man!"

PAO NIU
One of the rare Mandarin terms in Singlish. Basically the same as “pok”. 
See: Pok.

PAOTOH (contributed by trashkore)
To snitch, or let the cat out of the bag.
Mahmood : Eh butok lah! Which bastard paotoh to teacher that I carry handphone to school? Now kena confiscate!"

PASAL
Believed to be of Malay derivation, this means "business", as in "that's my business, not yours" rather than anything commercial.
"Eh, I tell you, ah, this thing is my pasal, so don't come and kachau, okay?" 

PATTERN TZUAY KUAY BADMINTON
Literally: more patterns than badminton. Phrase describing someone as extraordinarily complicated, or even devious.  Essentially saying that someone's wiles know no bounds.
"Wah lau, ask him to do anything, very difficult. He pattern tzuay kuay badminton."

PECAH (per-chah)
Malay for "broken" or "to break".
"Once you pay for the goods, if pecah already, that's your problem."   

PECAH LOBANG
A Malay phrase which literally means to break a hole.  It's used in the same way as the English phrase "to let the cat out of the bag."
"Don'ch tell him anything secret.  He's like the BBC like that, sure pecah lobang."

PEK CHEK
Hokkien term denoting exasperation or frustration.
"Wah lau, kena arrow this kind of job, si beh pek chek, man!"
See also: Bang. 

PENG SAN
Hokkien for "to faint".
"I saw the results only and I want to peng san."

PIA CHUI (pee-ah chwee) (contributed by akm)
Hokkien phrase meaning to get into unruly fights with gangsters.
"Wah lau, you for nothing go and stare at that Ah Beng, later sure pia chui one!"

PIAN CHIA'H (contributed by Kevin)
Hokkien term which literally translates as "cheat to eat". As opposed to "Tan Chia'h", it means doing something which may seem impressive to others but is actually quite easily done. Usually used when a person wants to show that he or she is humble.
Beng: "Wah, your computer (skills) very good leh!" 
Seng: "No, lah, pian jia pian jia only mah..." 

PINKERTON
A pejorative term originating from Puccini’s opera Madama Butterfly, describing local girls who will only go out with Caucasians. Now out of vogue. Probably more suited to addressing Caucasian men who have an Asian female fetish.
See: Sarong Party Girl.   

PLAY CHEAT
Inexplicably, to cheat.
"I warn you, ah, don't play cheat or I tell teacher then you know!"

PLAY PUNK
To provoke, irritate or aggravate.
"I told you not to do it, you still go and do.  Don't come and play punk with me, ah, I tell you first!"

PLAYED OUT
To be conned.
“Wah lao, I got played out by Johnny, man!” 

POK
A not especially polite way of describing a man pursuing the affections of a woman.
“Eh, she damn jude.  You think I should go and pok her?” 

PONTANG
To skive.
"I know it's a school day, but I decided to pontang."
See also: Siam; Tuang.  

POR
Hokkien term literally meaning "to carry". An act of sycophancy. Buttering someone up, or brown-nosing.
"Eh, I know you want good marks, but don't por the teacher until so obvious, can or not?"
See also: Angkat; Sah-kah; Sah-kah tzua.

POTONG
Malay for "cut off" or "amputate", in Singlish it is more specifically used to describe castration or being emasculated.
"Wah lao, his girlfriend dumped him for another woman, like that might as well potong, man!"

POTONG JALAN
Malay, literally meaning "to cut a (new) road". Often used in the context of stealing somebody's girlfriend (v. rarely boyfriend) away, but can also refer to other types of transactions where one party is being bypassed or cut off.
"I thought you my best friend one, how can you potong jalan Jenny?" 

POWDERFUL
Deliberate mispronunciation of "powerful".
"His body odour was damn powderful." 

POW KA LEOW
Comprehensive; all-encompassing.
"Wah lau, the Lexicon of Lah is damn pow ka leow. Everything also got."

PREMBRY
The correct pronunciation of 'primary'.
"I remember prembry school that time, hor, I was a class monitor."

PUAS (poo-ahss)
Malay for "satisfied", or "gratified".
"After my stingy boss gave me that kind of bonus, I went to scratch the bastard's car until puas."
See also: Song

PUI CHAO NUAH (contributed by Bernard Lee)
Literally, Hokkien for "to spit smelly spittle".  Describes being extremely fed up or disgruntled.
"Wah lan, I for nothing tio extra from my PC. Pui chao nuah!"

PUKI (contributed by Adam)
Malay expletive which is the equivalent of "Chee Bye" (vagina), it is derived from the Malay word "pukang", or crotch.

PUMCHEK (pahm-che'h)
Derived from a Malay mispronunciation of "puncture", it is now the default Singlish term for "flat tire".
"Yesterday my car pumchek on the AYE, damn leceh, man!"

Q

R

RABAK RABAK (rah-bahk)
Malay for "petting" or "making out". In Singlish, the continuous tense is "Rabaking".
1. "Alamak, such an ugly girl also can rabak rabak! You gila or what?"
2. "Eh, check out behind the bushes, lah.  Yusop and Yati are rabaking there."

READY ALREADY (reddy orreddy) (contributed by Stephen Tan)
A commonly-used redundancy to indicate a state of readiness. 
"Can we go now? I'm ready already."

RELAC/RELAC ONE CORNER
A Mat-ism, exhorting one to relax.  ‘Relac’ is ostensibly even more laid back than ‘relax’, as it is in the singular.  "Eh, Joe! Exam so far away. Relac one corner, lah."
See also Jangan Tension; Maintain Balan.  

REPEAT AGAIN
A commonly-used redundancy.
“I can’t hear you. Can you repeat again?”
See also: Say Again. 

ROJAK (roh-jah') (contributed by Minglun)
A salad of mixed vegetables taken with sauce.  Of Malay origin, it has been adapted by all races. In Singlish, it is used as an adjective, to describe something as being either eclectic, or just plain messy.
"This sort of multi-cultural event, ah, don't plan properly will come out all rojak."

ROSAK (roh-sah')
Malay for "damaged" or "spoilt".
"Adoi, Ramli, why you anyhow go and rabak my sister? You damn rosak, sial!"  

ROTAN (roe-tun)
Malay for "cane". It has two meanings in Singlish. The first is to receive a caning. It can also be used to describe a young girl as a "lolita" or "jailbait", as caning is often the sentence for engaging in or soliciting underage sex.
1. "I told Ah Seng not to employ that illegal Bangla. Wait he kena rotan, then he tzai see!
2. "These convent girls, ah, all damn rotan one."

RUGI (roo-ghee)
A term of Malay origin, it means “to lose out on an opportunity” or “to be disadvantaged”.  Hardcore Bengs pronounce it “loogi”
“I didn’t apply for the scholarship in time. Damn rugi big time, man.”