I. rev 1 /rev/ BrE AmE ( also rev up ) verb ( past tense and past participle revved , present participle revving ) [intransitive and transitive]
if you rev an engine, or if an engine revs, you make it work faster
rev up phrasal verb informal
if you rev up a system or organization, or if it revs up, it becomes more active
rev up for
They are revving up for one of the biggest fund-raising events ever organized.
rev something ↔ up
Investors keep putting money in U.S. companies, revving up the economy even more.
II. rev 2 BrE AmE noun [countable]
[ Date: 1900-2000 ; Origin: revolution ]
informal a complete turn of a wheel or engine part, used as a unit for measuring the speed of an engine SYN revolution