M'Shaiya Share definition Flag A stupid, annoying, out of conrtol girl. Who likes to lick every one she possibly can. She eats diarreha everyday. She has no friends. Never trust a M'Shaiya. I caught M'Shaiya eating diarreha again today. M'Shaiya by chickennugget123 March 28, 2013 Get the M'Shaiya mug.