Synonyms of underdeveloped

1 Syllable
poor
2 Syllables
lagging, latent, kidstuff
3 Syllables
vestigial, half-baked
4 Syllables
simple-minded, immature, atavistic, unrealized
5 Syllables
preliterate, impoverished, nonliterate, undeveloped, unactualized, unprogressive, disadvantaged