利口・利巧・悧巧・悧口|りこうrikou[0]heiban (flat)

1. na-adjective, nounclever; intelligent; bright; smart; wise; sensible; shrewd
   しかし、トニーは利口りこうな少年しょうねんではありませんでした。↗

   But Tony was not a clever boy.
2. na-adjective, nounwell-behaved (esp. of children and pets); obedient; goodusu. お〜

• Synonym賢いかしこいNeutralThe plain adjective for clever and the most common word in speech; 「利口」 also often praises animals and well-behaved children.
• Synonym賢明けんめいNeutralRefers to wise, sensible judgment (「賢明な判断」); stresses that a choice or action is right rather than quickness of mind.
• Synonym聡明そうめいWrittenWritten word for intelligence and quick understanding (「聡明な女性」); carries an appreciative tone.
• Synonym英明えいめいWrittenWritten word for outstanding judgment and wisdom; used mostly of rulers and leaders.
• SynonymインテリジェントNeutralLoanword for intelligent; used mostly in technical contexts (「インテリジェントビル」).
• Synonym利発りはつWrittenWritten word for children being bright and quick (「利発な子」); used mostly to praise children.
• Synonym明敏めいびんWrittenWritten word for a keen mind that grasps things quickly; rare.
• SynonymさといWrittenWritten adjective for quick, sensitive perception (「耳が聡い」「利に聡い」).
• Synonym穎悟えいごWrittenWritten word for exceptionally high natural intelligence; rare.
• Synonym怜悧れいりWrittenWritten word for a clear, sharp mind; seen mostly in character descriptions in novels.
• Synonym慧敏けいびんWrittenWritten word for a quick, agile mind; rare.
• Synonym抜け目ないぬけめないNeutralAdjective for shrewd and alert, never losing out; often carries a calculating nuance.
• Synonym穎敏えいびんWrittenRare written word for a quick, keen mind.
• Synonym抜け目のないぬけめのないNeutralA phrasing close in meaning to 「抜け目ない」; shrewd and worldly-wise (「抜け目のない人」).
• Related俊秀しゅんしゅうWrittenWritten word for a person of outstanding talent and intellect; rare.
• Related犀利さいりWrittenWritten word for sharpness and keenness (「犀利な分析」); often describes incisive writing.
• Related賢しいさかしいWrittenWritten word for clever, but can also carry a negative sense of acting too clever for one's own good.
• Related才気煥発さいきかんぱつWrittenFour-character idiom for brimming wit and quickness (「才気煥発な少女」).
• Related小賢しいこざかしいNeutralActing smart-alecky, showing off small cleverness (「小賢しい真似」); derogatory.
• Antonym鈍感どんかんNeutralDull and insensitive; the opposite of 「利口」 and 「聡い」.
• Antonym愚鈍ぐどんWrittenWritten word for dull-witted; the direct opposite of 「利口」.

Use 「利口」 for cleverness and for children or pets being well-behaved; in everyday speech 「賢い」 is the usual word. For wise judgment pick 「賢明」, for praising someone's intelligence 「聡明」, for shrewd, calculating types 「抜け目ない」, and for showing off cleverness 「小賢しい」. The opposite is 「愚鈍」.

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

1. 賢かしこい者もの、利発りはつな者もの。
2. 賢かしこい、利発りはつな、さかしい。
3. 聞ききわけのよい、わがままでない。
4. 抜け目ぬけめのない、ずるい、巧妙こうみょうな。