noun, noun which may take the genitive case particle 'no'
Used for works, projects, or collections that are not yet complete. Often appears in titles or descriptions of serialized works.
この小説は未完のまま作者が亡くなった。
The author passed away leaving this novel unfinished.
全集は未完に終わった。
The complete works remained incomplete.
未完成 is more common in everyday speech and can describe anything not yet finished, while 未完 is more literary and often used for artistic or scholarly works.
Compound of 未 (mi, 'not yet') and 完 (kan, 'complete'). The reading is on'yomi.