Thotties are promiscuous females, sluts.
Often like to participate in drinking and doing drugs. Most "Thotties" are often times young single mothers who live with their parents. They are typically someones "plaything" and are tooted and booted very quickly. Most men will not marry this type of female but will however spend a couple days partying with such and then move on. As a result a "Thottie" will end up single again, looking for another dude to get "Turnup" with, or they will end up with a baby.
Term made popular by the sensation from Chicago known as Chief Keef.
I ain't even playin tho
i make bitches fly like peter pan tho
That's why i just ask you
You's a alcoholic I ain't got no time for you
Is you off the molly if i book your flight is you gonna top me
Okay you got me I don't love no thotties
-Chief Keef "Love No Thotties"
The age at which single women without children realise that their biological clock is ticking, As a consequence they may lower their standards and increase their willingness to perform sexual acts as a matter of desperation in order to find a mate/sexual partner. They may also attempt to hook up with younger males as an attempt to elongate their youth.
The expression almost always refers to women, as men are thought to always be in this state.