効き目・利き目|ききめkikime[0]heiban (flat)

1. nouneffect; virtue; efficacy; impression
   その薬くすりの効ききめが現あらわれた。↗

   The medicine took effect.
2. nounone's dominant eye

• Synonym効能こうのうWrittenWritten/formal prose. The efficacy of medicines or hot springs, as in 「温泉の効能」; leans toward listing effects, while 「効き目」 is about whether it actually worked.
• Synonym効果こうかNeutralNeutral. The broadest word for effect, as in 「効果がある」 or 「効果音」; covers both speech and writing, wider than 「効き目」.
• Synonym実効じっこうWrittenWritten/formal prose. Actual, real-world effect, as in 「実効性のある対策」; centers on whether policies or measures really work.
• Synonym効力こうりょくWrittenWritten/formal prose. The power to produce an effect, as in 「薬の効力」; also the validity of laws and contracts, as in 「契約の効力」.
• Synonym効こうWrittenWritten/formal prose. Efficacy or benefit, mostly in the set phrase 「効を奏する」; rarely used on its own.
• Synonym利きききNeutralNeutral. Drug effectiveness or the dominant side, as in 「利き手」 or 「薬の効きが早い」; mostly used in compounds.
• Related甲斐かいNeutralNeutral. Whether something was worth doing, as in 「努力の甲斐がある」; focuses on whether the effort pays off.
• Related効験こうけんWrittenWritten/formal prose. Efficacy, typically of prayers to gods and Buddhas or of medicines; rare in modern Japanese.
• Antonym無効むこうNeutralNeutral. Invalid or no longer effective, as in 「無効になる」; the opposite of 「効き目」 actually taking effect.

Use 「効き目」 for the actual effect of a medicine or measure, as in 「効き目が現れる」; it also means one's dominant eye. For effects in general pick 「効果」; for the stated efficacy of medicines or hot springs, 「効能」; for whether an effort pays off, 「甲斐」. The opposite is 「無効」.

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

1. 効きいた印しるし。効能こうのう。効果こうか。
2. 両目りょうめのうち、実際じっさいに利きいている目め。