An angel. A princess. A term endearing the most beautiful girl in the world. The most special, most wonderful girl in the whole world.
Geraldine could not believe that nie-nie was actually his. What a lucky boy!
von Merriam Webster 22. August 2003
1 more definition
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!
von iamSoPC 8. November 2007