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going ahead; going first
preceding; coming before; being ahead (e.g. of the times); occurring first; happening prior
scoring first; getting off to a lead
stalker
先行発売のチケットを買ったよ。
I bought advance sale tickets.
彼が先行して調査を進めている。
He's advancing the investigation ahead.
先行きが不安で仕方がないんだ。
I can't help but worry about the future.