A nickname given to a really awesome female - derived from the word gnash, which means to grind your teeth in anger.
A 'Nasha' is a terrifying, fierce and tough female warrior who is on a mission for destruction. She prays on females who get in her way. She will psych out her pray with her piercing stare and terrifying gnashed jaw then attack when they least expect it.
"RRUUNNN - a Nasha is coming!!!!!"
"Please don't hurt me Nasha, i'm too young to die"
"I woke up black and blue after bumping into a Nasha last night!!"