昼夜ちゅうや Common Noun Adverb Noun English jmdict 1 noun (common) (futsuumeishi) adverb (fukushi)nouns which may take the genitive case particle 'no' day and night 警察が墜落事故の原因を昼夜休むことなく調査している。 The police are investigating the cause of the crash around the clock.