Today’s new word--dyad

A dyad consists of two. It’s two units treated as one; a couple, a pair. It comes from the Greek, dyas. I’ve never used this word. Have you? The context was academic, of course.

“The FAST team structures repetitive, positive interactions sequenced in dyads (parent to youth, parent to parent) and in small groups (the youth's family, peer groups for parents, peer groups for youth).” Huh?