rate

From Middle English rate, borrowed from Old French rate, from Medieval Latin rata, shortened from the Latin phrase prō ratā parte, meaning "according to a fixed part." That rata comes from ratus, "fixed," the past participle of rērī, "to think, judge, estimate" — which originally meant simply "to reckon or calculate."

What began as a Latin phrase about dividing something into a fixed proportional share narrowed over time into a single word for a measured amount or standard of comparison, the sense English still uses today.

There is also an unrelated Middle English word raten, "to scold, chide," from Old Norse hrata ("to refuse, reject"), which shares no connection to this sense of rate despite the identical modern spelling.