nie nie Share definition Flag Or "Ni Ni" is a shorter version of "Night night" or "Goodnight." Normally used in short hand messages. pronounced "N-Eye N-eye" Nie nie, don't let the bedbugs bite! nie nie by iamSoPC December 1, 2007 0 0 Get merch Get the nie nie mug. Buy Now — $32.95 See more merch