
to pledge; to vow; to promise; to swear
to have sexual intercourse (esp. between husband and wife); to share a bed
彼らは固く義兄弟の契りを結んだ。
They formed a firm pact as sworn brothers.
友情を契って固い握手を交わしました。
We pledged friendship and shook hands.
神の前で永遠の愛を契る儀式だった。
It was a ceremony to vow love before God.