"Buzo" is a Spanish word. One meaning is, at least in Peru, the whole "track suit". When we refer specifically to the pants, we say "pantalón de buzo". In, Colombia "buzo" is a kind of jersey, I think. Well I am sure now, because Tim is from England, Richemie Chery is from The US, and Profe José lives in the US, that you can't use "sport pants" as a synonym for"sweatpants" or the whole "tracksuit" Thanks for your answers.