Counts one occurrence of an action or event. Also used in sports for one round, game, bout, heat, or inning.
I've met him only once.
この試合は一回で決まる。
This match will be decided in one round.
I solved this problem on the first try.
Take two tablets of this medicine each time.
I've only met her once.
一度 and 一回 both mean 'once', but 一度 sounds slightly more formal or literary while 一回 is the everyday counting word.
一回 means 'once' and 二回 means 'twice'; they sit on the same counting scale for occurrences rather than being true opposites.
一回 is the plain counter for occurrences used in both speech and writing; いっぺん is an informal spoken alternative with the same meaning.
一回 means 'one time' (a single occurrence), while 数回 means 'several times' (a small number of repeated occurrences).
一回 (once) and 一階 (first floor) are pronounced identically but refer to completely different things—an occurrence versus a building level.
一回り looks similar to 一回 but 一回り means 'one round/one size/one 12-year cycle' while 一回 simply means 'one time, once'.
一回 means 'once' or 'one time', while 三回 means 'three times'; both are numeral+回 counter phrases that learners can mix up when adjusting the number.
one dose; one installment
first anniversary of a person's death
first round; first game
one revolution; one rotation
first time; first occurrence · first; initial
single-round contest; one-shot game; make-or-break match
Standard kanji spelling; the most common written form.
Numeral spelling, common in lists, schedules, and informal writing.
Compound of 一 (one) and 回 (counter for occurrences).