expression, ichidan verb
cross swords; engage in a duel
Literally or figuratively crossing swords; used for actual sword fights or heated debates.
二人の剣士が剣を交える。
The two swordsmen cross swords.
議論で彼と剣を交えた。
I crossed swords with him in a debate.
Compound of 剣 (sword) + を + 交える (to cross, exchange).