プログレッシブ和英中辞典(第4版)の解説
ひとまわり【一回り】
❶〔１周〕a round
池を一回りする
walk around a pond
彼は息子を連れて町を一回りした
He took his son around the town.
警備員はビル内を一回りした
The (security) guard made his rounds of the building.
❷〔十二支の〕one cycle of the twelve years of the Chinese zodiac
彼は私より一回り年上だ
He is twelve years 「my senior [older than I am].
❸〔大きさの一段階〕
それは一回り大きい
That is a [one] size larger.
彼は一回りも二回りも大きくなった
〔体が〕He has grown much bigger.／〔人柄が〕He has matured greatly.