look up any word, like cunt:
 
4.
A foul language term in Cantonese , mainly used in Hong Kong.

When someone did something stupid or doing something silly. We will usually call them " on 9 " - Which means " stupid penis " in english.

the number " 9 " is from the pronouciation of " penis " in Cantonese.

An excellent word for saying this to people in Hong Kong.
Mr.Tung is an on 9. ( Mr.Tung is a stupid penis )
Don't be on 9 la. ( Don't be stupid )
by Scottie August 25, 2004
 
1.
on9
Vulgar
Used in Hong Kong
Pronunciation: "on-gau" ("on" in English, "9" in Cantonese)
Meaning: stupid, thinking stupid
More: on99
Chief Exceutive Mr.Tung: If China is good, Hong Kong will be good. When Hong Kong is good, we are good too.
Citizen A: He's on9.
Citizen B: He's on99.
by HKboy February 20, 2005
 
2.
on9
adj. Very stupid or foolish.
Pronounced "on gau" (The 9 is pronounced in Cantonese)

Cantonese slang used mainly by young Hong Kong Chinese. First originated on the Internet (isn't everything) but soon spread to everyday speech.

Originates from two words:
The first part "on" comes from "On ghuy" - a cantonese slang word meaning foolish.
The second part "9" comes from "gau" - a cantonese slang word meaning penis.

Also used as part of the phrase "on9 zai" meaning foolish man/boy.
Dude 1: Wow, that silly mainlander squatting on the pavement looks so damn on9.

Dude 2: Shut up, you on9 zai.
by The loch monster August 08, 2006
 
3.
on9
stupid
chinese pronunciation
r u on9?
by urlifehk June 29, 2003
 
5.
on9
Online,Connected to the Internet
I've been on9 since yesterday.
by Knight Industries Two Thousand November 21, 2003