Yay? what does it mean here?

Question

i know this is dumb but i really dont know what it means when people say yay ( not the happy yay ) . for example, my hair was "yay" short and or this essay is " yay" long?

Answer 1

It just means "about".  It's usually accompanied by a hand gesture so you know "about" how long the hair or the essay is :)

Answer 2

i think it means big or small or just small idk!