一ひと回まわり小ちいさな

pre-noun adjectival

a size smaller; one size down

Used before a noun to describe something that is slightly smaller, often by one standard size or increment. Common in contexts like clothing, containers, or portions.

• このTシャツの一ひと回まわり小ちいさなサイズはありますか。

  Do you have this T-shirt in a size smaller?

• 一ひと回まわり小ちいさな鉢はちに植うえ替かえた。

  I repotted it into a pot one size smaller.