division into three; one third
Refers to splitting something into three equal parts, or one of those parts. Often used in contexts like dividing a sum, a space, or a task.
We split the cost into three and each paid 10,000 yen.
We divided the cake into three and ate it together.
Variant without okurigana; less common but still seen.
Formed from 三つ “three” and 割り “division”; わり retains its ordinary initial consonant and does not undergo rendaku.