also: だいしあい
noun
big match; important game
Refers to a high-stakes or highly anticipated sports match or competition.
明日はいよいよ大試合だ。
Tomorrow is finally the big match.
彼は大試合でいつも実力を発揮する。
He always performs well in important games.
試合 is a general term for a match or game, while 大試合 specifically emphasizes its importance or scale.
Compound of 大 (big, great) and 試合 (match, game).