Verb (5-dan, う, transitive)
1. to look at each other; to exchange looks
お互いに顔を見合って、笑った。We looked at each other and laughed.
Verb (5-dan, う, intransitive)
2. to correspond (to); to be proportionate (to); to be in keeping with; to offset; to counterbalance
この笑顔に見合う何かを、考えないとな。I have to think of something worthy of this smile.