不完全|ふかんぜんfukanzen[2]nakadaka (mid-high)

1. na-adjective, nounimperfect; incomplete; faulty; defective
   彼かれの計画けいかくはまだ不完全ふかんぜんな点てんが多おおい。↗

   His plan leaves much to be desired.

• Synonym不全ふぜんNeutralRefers to an organ or function not working fully; mostly medical, as in 「心不全」. Stresses impaired function rather than a general flaw.
• Synonym不備ふびNeutralPoints to holes or omissions in preparations or procedures, as in 「書類に不備がある」. Stresses gaps in arrangements, not overall imperfection.
• Synonym不十分ふじゅうぶんNeutralMeans not sufficient or falling short of what is required; stresses quantity or degree, while 「不完全」 stresses being flawed or incomplete.
• Related未完成みかんせいNeutralMeans not yet finished, whether still in progress or shelved; 「不完全」 stresses having defects regardless of whether it is complete.
• Related不徹底ふてっていNeutralDescribes work done half-way and not carried through to the end; stresses weak follow-through rather than inherent flaws.
• Related部分的ぶぶんてきNeutralMeans partial or localized, concerning only part of the whole; a neutral description with no sense of defect.
• Related手薄てうすNeutralShort of manpower or stock, as in 「警備が手薄」; stresses thin defenses or preparations.
• Related欠如けつじょWrittenWritten/formal prose; the lack of a quality one ought to have, as in 「責任感の欠如」; stresses the absence of something expected.
• Related不足ふそくNeutralShortage or lack; the most common of these words; stresses quantity falling short.
• Related欠けつNeutralNot actually a synonym: written 「欠」 it means a yawn or the kanji radical, unrelated to the sense of lacking in 「不完全」.
• Related至らないいたらないNeutralMostly humble self-deprecation for one's own insufficient ability or thoughtlessness, as in 「至らない点」.
• Related寸足らずすんたらずCasualColloquial; literally a little too short in length, and figuratively just slightly inferior; carries a figurative flavor.
• Antonym完全かんぜんNeutralAntonym: perfect and complete, lacking nothing; the opposite of flawed 「不完全」.

Use 「不完全」 for something flawed or incomplete, as in 「不完全燃焼」. For failing organs say 「不全」, for gaps in paperwork 「不備」, for shortfalls in amount 「不足」 or 「不十分」. 「未完成」 is simply unfinished; 「欠如」 is formal for a missing quality; 「完全」 is the antonym.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 欠かけたり違ちがっていたりして完全かんぜんでないこと。また、その様よう。