once-daily
UK[ˌwʌns ˈdeɪli]US[ˌwʌns ˈdeɪli]
adj
Happening, done, or taken once every day.
adv
Once every day.
Morpheme Breakdown
once
daily
once
one time
daily
per day
Etymology
The compound 'once-daily' is a transparent modern English formation that combines two common temporal adverbs to create a specific frequency term. 'Once' originates from the Old English word for 'one', its adverbial form solidifying the meaning of a single occurrence. 'Daily' derives from the Old English word for 'day', combined with an adjectival suffix. The logic of the compound is purely arithmetic, literally meaning 'one time per day', a meaning that has remained constant since its formation. This type of compounding is typical in English for creating precise technical descriptors, especially in fields like medicine and scheduling.
Analysis
Structure: once (one time) + daily (per day)
- once: From Old English ānes, genitive of ān (one), used adverbially to mean 'one time'. Origin: Proto-Germanic.
- daily: From Old English dæġlīċ (of a day, daily), from dæġ (day) + -līċ (-ly, forming adjectives). Origin: Proto-Germanic.
Examples
The patient was prescribed a once-daily medication to manage his blood pressure.
The supplement is most effective when taken once-daily with a meal.
The team holds a once-daily briefing to synchronize their progress.