3 letters:
mis

4 letters:
bice, dice, lice, mace, maia, mass, maya, mess, mike, mile, mime, mine, mire, miss, mite, moss, nice, rice, tice, vice, vise, mice

5 letters:
masse, meese, meyer, might, mites, moose, mouse, weiss

6 letters:
gneiss, mousse