知力・智力|ちりょくchiryoku[1]atamadaka (head-high)

1. nounintellectual power; mental capacity; intellect; intelligence; brains
   知力ちりょくでは誰だれも彼かれにはかなわない。↗

   No one equals him in intelligence.

• Synonym知能ちのうNeutralClose to 「知力」: the mind's power to understand and judge. Neutral and very common, especially in 「知能指数」 and 「人工知能」.
• Synonym知性ちせいWrittenWritten/formal prose. The ability to grasp principles and judge accordingly; also describes a person as cultured and intellectual.
• SynonymインテリジェンスWrittenWritten loanword. Means intelligence as intellect, but also intelligence in the sense of information or espionage; broader than 「知力」.
• Synonym頭脳ずのうNeutralNeutral, at home in speech and writing alike. Brains as the power to think and judge, as in 「頭脳明晰」.
• Synonym知的能力ちてきのうりょくWrittenWritten/formal prose. One's mental faculties for thinking and judging; a formal way to refer to intellectual ability.
• Related英知えいちWrittenWritten/formal prose. Superior wisdom marked by deep insight into the way things are; loftier than 「知力」.
• Related知恵ちえNeutralNeutral and very common in daily life. Wisdom as practical resourcefulness—clever ideas and know-how for handling problems.
• Related機知きちWrittenWritten/formal prose. Wit that adapts quickly to the moment, as in 「機知に富む」.
• Related才気さいきWrittenWritten/formal prose. Brilliance on open display; typically in 「才気煥発」.
• Related才さいNeutralNeutral. A one-character word for natural gift; typically 「才がある」, talent in a particular field.
• Related聡明そうめいWrittenWritten/formal prose. Describes a person as bright—quick to understand and clear in judgment.
• Related利口りこうCasualColloquial. Clever and sharp, said of people; also well-behaved and obedient, said of children and pets.
• RelatedエスプリWrittenWritten loanword. Wit and esprit—cleverness with a French-flavored, elegant humor.
• Related理解力りかいりょくNeutralNeutral. Narrower and more specific than 「知力」: the capacity to take in and grasp things—comprehension alone.
• Related理知りちWrittenWritten/formal prose. Reason: judging by principle and logic rather than by instinct or emotion.
• Related才知さいちWrittenWritten but rare. Talent combined with wisdom; suggests bright, sharp cleverness.
• RelatedとんちCasualColloquial. Ready wit for the situation at hand; typically in the phrase 「頓知を利かせる」.
• Related悟性ごせいWrittenWritten/formal prose. A philosophical term for the faculty of intuitive understanding; usage is specialized.
• Related才力さいりょくWrittenWritten but rare. Innate ability or talent—not confined to mental power.
• Related巧知こうちWrittenWritten but rare. Ingenious cleverness; leans toward skill and adroitness more than 「知力」.
• Related学習能力がくしゅうのうりょくNeutralNeutral. More specific than 「知力」: the ability to understand and master new things.
• Related頓才とんさいWrittenRare. On-the-spot quickness and adaptability; close to 「頓知」.
• Antonym愚かおろかNeutralAntonym. Foolish—lacking in thought and judgment; the opposite of having 「知力」.

Use 「知力」 for intellectual power—the mind's capacity to think and understand—often paired with 「体力」 as in 「知力と体力」. For the ability to understand and judge, 「知能」 is close and common in 「知能指数」 and 「人工知能」; for everyday wisdom and clever solutions, pick 「知恵」. Written alternatives include 「知性」, 「英知」 (deep insight), 「理知」 (reason over emotion) and 「機知」 (quick wit, 「機知に富む」); neutral 「頭脳」 means brains, as in 「頭脳明晰」. Narrower terms: 「理解力」 and 「学習能力」. Colloquial 「利口」 covers bright or well-behaved people; the antonym is 「愚か」.

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

1. 知恵ちえの働はたらき。