Other forms: rates
A rate is how fast something happens, or a fixed charge. The birth rate, an hourly rate, interest rates.
It is always a quantity per something — per hour, per thousand people, per year — and leaving out the per is how misleading statistics get made. In Britain, rates were the old local property tax, and business rates still are. Note that the Latin means a fixed part, from pro rata.
1nounrateHow fast something happens, per unit of time.
“The nurse checked the baby's heart rate every hour.”
2nounfixedA fixed charge.
“The hotel offers a special rate for students.”
Too few real examples of this word to estimate which sense is commonest.
rate is a measure or charge.
Medieval Latin rata comes from the phrase pro rata parte, according to a fixed part, from ratus, fixed. Ratio and reason come from the same reckoning.
Proto-Indo-European
*h₂er-
Latin
prō ratā parte — according to a fixed part
Medieval Latin
rata
Old French
rate
Middle English
rate
English, today
rate
Built from
From Middle English rate, from Old French rate, from Medieval Latin rata, from Latin prō ratā parte (“according to a fixed part”), from ratus (“fixed”), from reor (“think, deem, judge, estimate", originally "reckon, calculate”).
Etymology from Wiktionary, CC BY-SA