usage: amount of a charge or payment relative to some basis; "a 10-minute phone call at that rate would cost $5"
3. rate, charge per unit, charge
usage: the relative speed of progress or change; "he lived at a fast pace"; "he works at a great rate"; "the pace of events accelerated"
4. pace, rate, temporal property
usage: a quantity or amount or measure considered as a proportion of another quantity or amount or measure; "the literacy rate"; "the retention rate"; "the dropout rate"