late 15th century (as an alchemical term meaning ‘distil something in a closed container, allowing condensed vapour to return to the original liquid’): from Latin circulat- ‘moved in a circular path’, from the verb circulare, from circulus ‘small ring’ (see circle). circulate (sense 1) dates from the mid 17th century
15世紀後半(錬金術用語として「密閉容器で何かを蒸留し、凝縮した蒸気を元の液体に戻す」という意味):ラテン語の circulat- 「円形の経路で動く」、circulus「小さな輪」から動詞 circulare に由来(circle を参照)。