Entry 1 sense Webster, 1913 Sidewinder /sīd'-wīnˌ-dẽr/ · Side·wind·er · IPA /ˈsaɪd.waɪn.dɚ/ 01 n. See Horned rattler, under Horned. 1. See Horned rattler, under Horned.(Zool.) See: Horned