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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 Feb 20, 2005 add a video
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.
3. on9
stupid
chinese pronunciation
r u on9?
by urlifehk Jun 29, 2003 add a video
4. on9
Online,Connected to the Internet
I've been on9 since yesterday.
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