Green’s Dictionary of Slang

dumbellina n.

[dumb-bell n. + fem. sfx -ina + pun on Disney character Thumbelina]

(camp gay) a fool.

1980

Maledicta IV:2 (Winter) 227: Dora (Dumb Dora) and Dumbo or Dumbellina (from Disney’s cartoon elephant and dumbbell) are heard.