noun
Specifically the opening phase of board games like go or shogi, where players establish their initial positions.
彼は序盤から積極的に攻めた。
He attacked aggressively from the opening.
noun
early stages; initial phase; outset
General use for the beginning part of any process, event, or period. Common in news and everyday speech.
The election campaign became a fierce battle from the early stages.
プロジェクトはまだ序盤です。
The project is still in its initial phase.