rate has 8 distinct synonyms spread across 4 of its 7 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
a magnitude or frequency relative to a time unit
“they traveled at a rate of 55 miles per hour”
Synonyms, antonyms and the broader and narrower relations for rate come from Princeton University’s WordNet. Full sources and licences.
amount of a charge or payment relative to some basis
“a 10-minute phone call at that rate would cost $5”
the relative speed of progress or change
“he lived at a fast pace”
a quantity or amount or measure considered as a proportion of another quantity or amount or measure
“the literacy rate”
assign a rank or rating to
“how would you rank these students?”
be worthy of or have a certain rating
“This bond rates highly”