means The speed at which a piece of music moves, or by extension the pace of any activity or process.

from Straight from Italian tempo, meaning 'time,' which descends from Latin tempus — the same root that gives us 'temporal' and 'tempest.' Italian became the lingua franca of Western music, so musicians across Europe borrowed its words wholesale: tempo, allegro, adagio. So when you set the tempo, you're literally setting the 'time.'