expression, noun
one third; a third
Standard fractional expression; used in mathematical, everyday, and formal contexts.
ケーキの三分の一を食べた。
I ate one third of the cake.
参加者の三分の一は女性だった。
One third of the participants were women.
Compound of 三 (san, 'three') + 分 (bun, 'part') + の (no, possessive particle) + 一 (ichi, 'one'), literally 'one of three parts'.