Synonyms of simple-minded

1 Syllable
slow, late, dull
2 Syllables
naive, duller, numbskull, simple, dense, checked, stupid, gorked, dullest, delayed, behind, dumdum, lamber
3 Syllables
guileless, slow-witted, unjaded, retardo, subnormal, retarded, moronic, arrested
4 Syllables
imbecile, feeble-minded
5 Syllables
underachieving, undeveloped
6 Syllables
underprivileged, underdeveloped