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start; beginning
試合の出だしから差がついた。
A gap opened up right from the start of the match.
曲の出だしだけで名曲とわかった。
Just the opening of the song told me it was a classic.
プレゼンは出だしが肝心で、冒頭の一言で聴衆の心を掴んだ。
The opening is everything in a presentation, and the first words grabbed the audience.