quantity (n.) Look up quantity at Dictionary.com
early 14c., from Old French quantite (Modern French quantité), from Latin quantitatem (nominative quantitas, coined as a loan-translation of Greek posotes) "relative greatness or extent," from quantus "of what size? how much? how great? what amount?," correlative pronomial adjective, from quam "in what manner, to what degree, how greatly, how, how much." Latin quantitas also is the source of Italian quantita, Spanish cantidad, Danish and Swedish kvantitet, German quantitat.