Terrassa is a city in the east central region of Catalonia, in the province of Barcelona, comarca of Vallès Occidental, of which it is the cocapital along with Sabadell. The name "Terrassa" may well be a contraction/corruption of late Latin: 'terra ix ipsa' -> proto-aragonese 'terra-iš-sa' (Eng: 'that avian/'cool' place') potentially conflated with 'terra-ès-sà' "safe-place/clean-place".