Dictionary

BMX en · NOUN

Initialism of bicycle motocross.

(uncountable) Bicycle motocross, a form of cycling on BMX bikes, originating in California in the 1970s.
- “When I was in Switzerland going through rehab, literally, I was like, ‘What’s the point? I’m going through so much pain right now and BMX has given me a lot of grief,’” said Sakakibara. 2024 July 9, Martynas Ruseckas, “After her brother suffered a brain injury in a bike crash, this Olympic BMX rider has a new perspective on what success means”, in CNN, archived from the original on 12 Jul 2024:
(countable) A BMX bike.
- In the end, why not be happy with both, with the BMXes and the pentathlons, with the swans of synchro and the Quasimodos of wrestling? Sweet. 2008 August 21, “The old school survives at the Olympics, amid new events”, in The New York Times, archived from the original on 23 Jan 2025:

Spelling	Features	Labels	Source
BMXs	Number=Plur		lexicographic
BMXes	Number=Plur		lexicographic

fr bicross (sport) · fr BMX (type of bicycle) · fr BMX (sport) · fr vélocross (type of bicycle) · fr bicross (type of bicycle) · fr vélocross (sport)

Initialism of bicycle motocross.

(intransitive) To ride a BMX bike.
- Yeah, flippity trick things are fun. I've got a friend who has BMXed for 15-16 years! He rules, and he used to be sponsored. 1997 June 17, KrUtCh [username], “Re: Skate-boarders...losers?”, in alt.skate-board (Usenet):
- I BMXed from 1978 (my first race) till not too long ago. Although I don't see too many freestylers in the net, I get in touch with quite a few ex-BMXers like myself on rec.bicycles.off-road (I'm cross-posting to it). 1995 February 21, Joao de Souza, “Re: B.M.X... Flatlanders and Freestylers”, in rec.bicycles.misc (Usenet):

Spelling	Features	Source
BMXing	Tense=Pres, VerbForm=Part	lexicographic
BMXes	Number=Sing, Person=3, Tense=Pres	lexicographic
BMXed	Tense=Past, VerbForm=Part	lexicographic
BMXed	Tense=Past	lexicographic
BMXs	Number=Sing, Person=3, Tense=Pres	lexicographic