to go before someone or to act beforehand (to forestall or anticipate); to gain an advantage by acting earlier.
我が社は他社より先んじて新製品を市場に投入した。
Our company put a new product on the market ahead of other companies.
彼は市場の動きを先んじて読み、投資を行った。
He anticipated market movements and made investments ahead of time.
会議には先んじて到着し、席を確保した。
He arrived at the meeting early and secured a seat.