完全|かんぜんkanzen[0]heiban (flat)

1. na-adjective, no-adjectiveperfect; complete
   そして書かかれていることはすべて完全かんぜんにはっきりと書かかれている。↗

   And then everything that was written was completely clear.

• Synonym完璧かんぺきNeutralFlawless, with not a single defect; stresses the absence of flaws more than 「完全」, which centers on completeness and thoroughness.
• SynonymパーフェクトNeutralLoanword for something flawless; rates performances and results, and also means a perfect game or full marks. Unlike 「完全」, it does not stress being complete.
• Synonym文句なしもんくなしCasualColloquial: beyond criticism or dispute, as in 「文句なしの優勝」.
• SynonymすっかりNeutralAdverb for having turned completely into a state, as in 「すっかり忘れた」; not used before a noun.
• SynonymまるっきりCasualColloquial adverb, mostly with a negative: not at all, or completely.
• SynonymまったくNeutralAdverb: completely, truly; with a negative it means not at all; also an exclamation like 'good grief'.
• Synonym万全ばんぜんWrittenWritten style: leaving nothing to chance, fully prepared, as in 「万全を期す」「万全の態勢」.
• Synonym完全無欠かんぜんむけつWrittenFour-character idiom, written style: perfect and without any flaw, stronger in tone than 「完全」.
• Synonym無欠むけつWrittenWritten style: having no defects; mostly seen in set phrases like 「完全無欠」 and rarely used alone.
• Related上々じょうじょうNeutralExcellent, going very well, as in 「出来は上々」; judges the result as good rather than calling it complete.
• RelatedバッチリCasualColloquial adverb: just right and sure to succeed, as in 「準備はバッチリ」.
• Related完備かんびNeutralFully equipped with all the necessary facilities, conditions, materials and so on, as in 「冷暖房完備」; 「完全」 is a general word for lacking nothing and has wider use.
• Related一切いっさいNeutralAll, everything; often with a negative to mean not at all or none whatsoever, as in 「一切関係ない」.
• Related十全じゅうぜんWrittenWritten style: perfect in every way and thorough, as in 「十全の準備」.
• Related完膚なきまでかんぷなきまでWrittenWritten idiom: thoroughly, leaving nothing intact, as in 「完膚なきまでに叩きのめす」.
• Related全備ぜんびWrittenWritten and rare: fully equipped and complete; 「完備」 is the usual word.
• Related徹頭徹尾てっとうてつびWrittenFour-character idiom, written style: from start to finish, through and through, as in 「徹頭徹尾反対する」.
• Antonym不完全ふかんぜんNeutralAntonym: lacking something, incomplete, as in 「不完全燃焼」.

Use 「完全」 for something lacking nothing or done thoroughly. For flawless perfection say 「完璧」 or 「パーフェクト」; for preparation that leaves nothing to chance, 「万全」; for fully equipped facilities, 「完備」. In casual speech 「バッチリ」 covers preparations, and the adverbs 「すっかり」 and 「全く」 mean 'completely'. 「完全無欠」 and 「十全」 are written intensifiers; 「上々」 praises a good result; 「一切」 and 「丸っきり」 go with negatives; 「不完全」 is the antonym.

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

1. 必要ひつような要件ようけんをすべて具備ぐびし、欠かけることがないこと、又またはその様よう。