rev

The word "rev" is a 20th-century abbreviation of "revolution," a term which entered English from Old French and ultimately from Latin revolutio, meaning "a rolling back." The Latin derives from revolvere ("to roll back"), itself from re- ("back") and volvere ("to roll"). In mechanical contexts, a "revolution" refers to one complete turn of an axis or engine component. By the early 1900s, "rev" emerged as a convenient slang term in automotive and engineering fields, first as a noun for a single engine revolution and later as a verb meaning to cause such revolutions to increase.

The word is a clipping or shortening of the noun "revolution," specifically in its mechanical sense. It is not productively composed of smaller, independent morphemes in its current form.