na-adjective, noun
half-baked; insufficient; half ripe
Describes something that is incomplete, immature, or not fully developed, often with a negative connotation. Can refer to skills, ideas, or literal ripeness.
彼の計画は半可で、実現は難しい。
His plan is half-baked and difficult to realize.
この果物はまだ半可だから、もう少し待ったほうがいい。
This fruit is still half ripe, so you'd better wait a little longer.
中途半端 is more common and means 'halfway' or 'incomplete', often used for actions or states. 半可 is less frequent and can specifically imply immaturity or lack of thoroughness.
未熟 means 'unripe' or 'immature' and is more formal. 半可 is more colloquial and carries a stronger sense of being insufficient or poorly done.
The word 半可 is composed of 半 (half) and 可 (acceptable/possible), suggesting something that is only half acceptable or half done. The exact historical derivation is uncertain, but it likely emerged as a colloquial term for incompleteness.