noun which may take the genitive case particle 'no', noun
well-matched; suitable; becoming
Often used for couples or pairs that look good together, but also for things that suit a person or situation. The 'no' adjective form is common (似合いの).
Those two are a really well-matched couple.
彼女にはそのドレスがとても似合いだ。
That dress really suits her.
Those two make a well-matched couple.
I think he and she really suit each other.