noun
one box; one container
Refers to a single box or container, often used when counting or referring to one unit of something packaged.
お菓子を一折り買った。
I bought one box of sweets.
一箱 is a more common and general word for 'one box', while 一折り is less frequent and may imply a specific type of container or packaging.
Compound of 一 (one) and 折り (folded container/box). The exact historical derivation is uncertain, but the word is conventionally associated with a single box or container.