Adagio is a music word. It tells you to go slowly, and it can also name a slow piece, or the slow part of a longer piece. On a score it may sit as an instruction: play this adagio. Ballet uses it too, for slow, controlled movement. Like many words on a classical page — allegro, andante, piano — English borrowed it from Italian and mostly kept it. We do not write “slowly” on the score and call it the same thing. It is at home in concert programmes and music class, not in everyday chat about walking down the street. Though actually, “slow” is relative. Adagio is slower than andante, but conductors still argue about how slow is slow, and a student’s adagio may not match a famous orchestra’s. It can be a noun (an adagio by Mozart) or sit more like an adverb/adjective in music talk (the movement is adagio). It is not a person’s name, and it is not adage, the wise old saying.