rate

1. The proportional relationship between one amount, value etc. and another. (countable, uncountable) · At the height of his powers, he was producing pictures at the rate of four a year.
2. Speed. (countable, uncountable)
3. The relative speed of change or progress. (countable, uncountable) · The rate of production at the factory is skyrocketing.
4. The price of (an individual) thing; cost. (countable, uncountable) · He asked quite a rate to take me to the airport.
5. A set price or charge for all examples of a given case, commodity, service etc. (countable, uncountable) · Postal rates here are low.
6. A wage calculated in relation to a unit of time. (countable, uncountable) · We pay an hourly rate of between $10 – $15 per hour depending on qualifications and experience.
7. Any of various taxes, especially those levied by a local authority. (countable, uncountable) · I hardly have enough left every month to pay the rates.
8. A class into which ships were assigned based on condition, size etc.; by extension, rank. (countable, uncountable) · This textbook is first-rate.

Plural rates