1. standing facing each other (e.g. mountains, buildings); standing opposite each other
川を挟んで二つの山が対峙している。Two mountains stand facing each other across the river.
2. confrontation; squaring off against (adversaries, armies, forces); standing off against; holding one's own with
しかし今、彼女は堂々と敵に対峙している。But now, she is standing boldly against the enemy.