to lead; to take the lead (in doing something)
to precede; to go before; to take precedence
to die before (esp. one's spouse, parents, etc.)
to be a prerequisite
彼はいつも皆に先立つ。
He always leads everyone.
その出来事に先立って準備した。
I prepared prior to that event.
隊長は危険を顧みず先立った。
The captain led without regard for danger.