BMX /biː ɛm ˈɛks/noun 2verb 1forms 4 noun2 •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 •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 verb1 •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 formsBMXed · BMXing · BMXes · BMXs