Entry 1 sense Webster, 1913 Tetrasyllable /tĕtrəsĭʹləbl/ · Tet·ra·syl·la·ble · IPA /tɛtɹəˈsɪləbl/ 01 n. A word consisting of four syllables; a quadrisyllable. 1. A word consisting of four syllables; a quadrisyllable.