A female, typically under the age of 30 who loves to publicly exhibit her armpits when excited in some way by pumping her fists into the air while shouting WOO! (sometimes WOO WOO). Whilst alcohol is a typical prequisite to becoming a WOO girl, it is not required.

Woo-girls: first heard on "How I met your Mother" accurately describes the type of "weekend warrior princess" who goes out in the company of several other Woo girls. Behavior is usually spotted by shouting "WOO" whenever a. drinking shots, b. ordering another round of drinks, c. shouting at pedestrians while travelling, d. entering or leaving a club or bar.
Generally the life of the party, or so they will tell you.

A Woo Girl is one of those freshman college girls who runs with a pack of other freshman college girls. At 3:00 am on any given weekday morning she can be heard through a sliding glass door, ten stories up, in Five Points in Columbia, SC, (or possibly any other college town) drunk as a coot and yelling "WOO!" over and over again and it wakes you up and makes you angry because you have to work in the morning or you have an 8:00 am class.

n. 1. A yeah dude in female form

2. a girl who shakes her ass and goes "woooo" when she gets a drop of alcohol in her

A name given to young girls who love to party and go out boozing and like to shout "WOO" with the rest of their Woo-girl friends. Typically seen at a bar/party scene acting loud and obnoxious, posting everywhere on social media for clout and recognition.