Denshi Jisho — Online Japanese dictionary

かい effect; result; worth; use; avail
Noun 
こう efficacy; benefit; efficiency; effect; result; success
Noun 
きく 1: to be effective; to show effect;
2: to do its work; to carry out its function well;
3: to be possible to use
Common word, Godan verb with ku ending, Intransitive verb 
きき effectiveness (esp. of drugs)
Noun 
こうか effect; effectiveness; efficacy; result
Common word, Noun, No-adjective 
じこう 1: statute of limitations; lapse of rights after a period of time; prescription (including acquisitive and extinctive prescription);
2: ageing; aging
Common word, Noun 
むこう invalid; no effect; unavailable; illegal
Common word, Na-adjective, Noun, No-adjective 
いこう great effect
Noun 
ききめ effect; virtue; efficacy; impression
Noun 
きこう remarkable effect
Noun 
ちこう delayed effect
Noun 
よこう aftereffect; after effect
Noun 
き目 ききめ effect; virtue; efficacy; impression
Common word, Noun 
こうのう effect; efficacy; virtue; benefit
Common word, Noun 
こうよう use; utility; effect; benefit
Common word, Noun 
こうりつ efficiency; efficacy; performance; utility factor
Common word, Noun 
じっこう practical effect; efficacy; efficiency
Common word, Noun 
そっこう immediate effect; instant effect
Common word, Noun 
はっこう coming into effect
Common word, Noun, Suru verb 
ゆうこう validity; legality; availability; effectiveness
Common word, Na-adjective, Noun 
こうけん efficacy; effect
Noun 
しっこう lapse; abatement; invalidation
Noun, Suru verb 
そうこう efficacy
Noun, Suru verb 
そっこう speedy effect
Noun 
たっこう great efficiency
Noun 
とっこう of particular efficacy
Noun 
やっこう efficacy of a drug or medicine
Noun 
目が めがきく to have an eye for
Expression, Godan verb with ku ending 

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