This is the 2529th most frequent Japanese word.
呼び
"呼び" means "call" or "invitation."
呼び is used to mean 'called someone or something by a name or title'.
彼女は私を『友達』と呼びました。
She called me a 'friend'.
呼び in this context pertains to the act of addressing or calling someone in a reciprocal manner.
お互いを呼び合うことは大切ですね。
It's important to call out or address each other.
呼び here is part of 呼び声 (yobigoe), meaning 'call' or 'cry', denoting the sound made by the bird.