underdeveloped (adj.)

• backward
• behindhand
• callow
• coarse
• crude
• defective
• deficient
• embryonic
• failing
• immature
• inadequate
• incomplete
• lacking
• missing
• part
• partial
• patchy
• reductive
• rough
• roughhewn
• rude
• rudimentary
• scant
• scanty
• scrappy
• short
• shy
• simplistic
• sketchy
• stunted
• uncultivated
• uncultured
• uncut
• undeveloped
• unfinished
• unformed
• unhewn
• unpolished
• unprocessed
• unprogressive
• unrefined
• untreated
• wanting