Demi \d(e)-mi\ as a girl's name is pronounced DEH-mee, deh-MEE. It is of French and English origin, and the meaning of Demi is "half". Also short form of Demetria. Actress Demi Moore. Demi has 4 variant forms: Demee, Demia, Demiana and Demie. Baby names that sound like Demi are Damia, Dama, Dumia and Tami. View a list of the 6 names that reference Demi.