undeveloped (adjective) undeveloped: immature
Sinonime: abortive, backward, behindhand, embryonic, half-baked, ignored,
inchoate,
incipient,
inexperienced,
latent,
potential,
primitive,
primordial, unactualized, underdeveloped, unevolved, unprogressive, untaught, untrained
Antonime: adult,
developed,
grown,
mature