'FM' originates from English, specifically the words 'frequency modulation', where 'frequency' ultimately derives from Latin 'frequentia' meaning 'repeated occurrence' and 'modulation' derives from Latin 'modulatio' meaning 'a measuring or regulating (of sound)'.

'frequency modulation' was developed and popularized in the early 20th century (notably by Edwin H. Armstrong in 1933) to describe the technique of varying a carrier wave's frequency; the abbreviation 'FM' came into common usage as broadcasting using that technique expanded in the mid-20th century.

Initially it referred specifically to the technical process of varying a signal's frequency; over time it broadened in common use to denote radio broadcasts transmitted by that method and the FM radio band itself.