surfboard UK /ˈsɜːfˌbɔːd/US /ˈsɝfˌbɔɹd/noun 1verb 1forms 3 noun1 •A shaped waterproof plank, usually made of wood or foam and reinforced plastic, used to surf on waves.One shark attacked the surfboard. verb1 •To use a surfboard; to surf. formssurfboarded · surfboarding · surfboards