‘朝夕’ literally combines ‘朝’ (zhāo), meaning ‘morning’, and ‘夕’ (xī), meaning ‘evening’. Together, they form a classical two-character compound that originally denoted the full cycle of a day — from dawn to dusk. In modern usage, it functions both as a noun meaning ‘morning and evening’ and as an adverb meaning ‘constantly’, ‘continuously’, or ‘day in and day out’, emphasizing frequency and closeness in time.

This word carries a poetic or literary tone and is common in formal writing, idioms (e.g., 朝夕相处), and expressions of enduring relationships or habitual actions. It often implies intimacy, persistence, or inevitability — not just temporal proximity but emotional or practical continuity. Unlike casual time markers like 每天, 朝夕 suggests deeper regularity or inseparability, making it especially fitting for describing close companionship, lifelong habits, or inevitable natural rhythms.