expression
first out; going first; leading off
Used in contexts like games, competitions, or sequences where someone or something is the first to appear, act, or be presented.
じゃんけんで先出しはグーに決めた。
In rock-paper-scissors, we decided that the first move would be rock.
会議では、新人が先出しで意見を述べた。
At the meeting, the newcomer spoke first and gave their opinion.