Tries too Hard. Used to describe when someone literally tries too hard at impressing someone, or when they react in an extreme manor at something. Like when someone reacts extremely at finding a pen. Can be used to describe people like the teacher's pet or the tri-hard. Used discreetly.
Person One: Holy crappers! Did you see Emily TTH-ing in photography class today?
Person Two: Yeah I know! She was trying wayyy too hard at "being the best". SO annoying!