Best definition
The sound Waluigi (From the Mario Series) makes.

WA! Waluigi Get You Next Time Cheaters!
WA: define #2
An expression for ultimately overpowering joy, excitement and/or anticipation.

Wa? Wa! wa…. wA, Wa, wAAAAAAA?!
WA: define #3
Short for Wife Alert! When you and a friend are IM-ing, and the wife walks in the room, you give the friend a heads up by typing WA, WA, WA!!!

WA, WA, WA!!!!!

WA: define #4
western australia. the state on the west side of the continent.
capital of wa is perth
WA: define #5
(postposition, Japanese)

The Japanese postposition (like a preposition except after a word) “wa” is the topic marker, which identifies the topic (duh) of the sentence. The literal meaning is “As for (noun).” Usually the topic and the subject are the same thing, but only if the topic has already been introduced; otherwise, you use the subject marker “ga.” Additionally, “wa” can be used to indicate contrast or emphasis of the subject. The way “wa” is being used depends on context and intonation.

Topic: Watashi wa koukousei desu. (“I am a high school student.”)

Contrast: Biiru wa nomimasu ga, wain wa nomimasen. (“I drink beer, but I don’t drink wine.”)

As an aside: Wa is not a verb; verbs are always at the end of a sentence in Japanese. Wa is not the Japanese copula, “desu” is; all wa does is tell you what the hell is being talked about. Don’t be stupid and think of it any other way.

WA: define #6
To use oranges for sexual pleasure. More tame version of Za as oranges are less zingy (see ‘Za’)
“Do you want to Za tonight?”

“No, I’ll Wa you though?”
WA: define #7
An Irish term commonly used to describe a person of traveller background but also used to describe any uncultured, ill-mannered person. Similar to scobe and knacker with similar dress sense.
Jaysus those look their from Wa’s of Limerick…