expression, ichidan verb
take advantage of an opportunity; seize the chance
A somewhat formal or literary expression meaning to act when a favorable moment arises. Often used in strategic or narrative contexts.
彼は相手のミスに機に乗じて一気に攻めた。
He seized the opportunity of his opponent's mistake and attacked all at once.
好機に乗じて
They took advantage of a favorable opportunity to enter a new market.