IPA: //trɪˈsɪl.ə.bəl//
KK: /trɪˈsaɪləbəl/
A word that has three syllables.
The word 'elephant' is a trisyllable because it has three distinct syllables.
Trisyllable → It is formed from "tri-" (meaning three) and "syllable" (from Greek "syllabē", meaning a unit of speech or a spoken part). The word "trisyllable" refers to a word that has three syllables.
Think of 'tri-' meaning three, and 'syllable' as a unit of speech — so a trisyllable is a word made up of three speech parts.