不備|ふびfubi[1]atamadaka (head-high)

1. na-adjective, no-adjectivedefect; deficiency; imperfection; inadequacy; lack
2. expressionYours in hastevalediction of a letter

• Synonym欠陥けっかんNeutralStructural or functional defects, as in 「欠陥住宅」; 「不備」 is about incomplete preparations or paperwork rather than flaws built into something.
• Synonym欠点けってんNeutralThe broadest word for faults or shortcomings, mostly of people or things; it does not specifically refer to gaps in paperwork or arrangements.
• Synonym瑕疵かしWrittenWritten/formal prose; a flaw or defect, also used in legal contexts, as in 「瑕疵担保」 and 「手続きの瑕疵」.
• Synonym不完全ふかんぜんNeutralIncomplete, stressing that a part is missing; widely applicable.
• Synonym不十分ふじゅうぶんNeutralInsufficient, stressing that the degree falls short, as in 「説明不十分」.
• Synonym欠けつWrittenWritten/formal prose; lack or vacancy, mostly in compounds such as 「欠員」 and 「欠席」.
• Related不足ふそくNeutralInsufficiency or shortage, of quantity or degree, as in 「準備不足」 and 「説明不足」; often forms compounds.
• Related不全ふぜんWrittenWritten/formal prose; a state or function failing to work fully, as in 「心不全」 and 「機能不全」.
• Related難点なんてんNeutralA fault or sticking point, often used to evaluate products or proposals; 「不備」 is about incomplete preparations or procedures.
• Related不徹底ふてっていNeutralNot carried through to the end, stressing that something was not done thoroughly; it criticizes the way things are done, not gaps in paperwork.
• Related手落ちておちNeutralAn oversight, stressing the carelessness of the person responsible, as in 「こちらの手落ち」.
• RelatedデメリットNeutralA loanword meaning drawbacks or disadvantages, used in business; it stresses the bad side of something rather than missing items.
• Related欠如けつじょWrittenWritten/formal prose; the absence of something one should have, said mostly of abilities or awareness, as in 「常識の欠如」; 「不備」 is about preparations or procedures.
• Related短所たんしょNeutralShortcomings of a person or thing, the counterpart of 「長所」, as in 「この案の短所」.
• Related不具合ふぐあいNeutralA malfunction of machines or systems, a technical-sounding term; not used for incomplete documents.
• Antonym完備かんびNeutralAntonym: fully equipped and complete, the direct opposite of 「不備」, as in 「設備完備」.
• Antonym完全かんぜんNeutralAntonym: perfect, with nothing missing; the opposite of 「不備」, which implies gaps or omissions.

Use 「不備」 for incomplete documents, procedures or preparations, as in 「書類の不備」 and 「不備があればご連絡ください」. For structural or functional defects say 「欠陥」, for an oversight by the person responsible 「手落ち」, and for a machine or system malfunction 「不具合」. 「欠点」 and 「短所」 cover shortcomings in general, 「不足」 and 「不十分」 shortfalls in amount or degree, and 「完備」 is the antonym for fully equipped.

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

1. 備そなえが不足ふそくしていること。十分じゅうぶんに整ととのわないこと。
2. 文意ぶんいが不完全ふかんぜんであること。手紙てがみの末尾まつびに添そえる言葉ことば。不一ふいつ。不具ふぐ。