IPA: /ˌmʌl.tɪˈsɪl.ə.bɪk/
KK: /mʌltiˈsɪləbɪk/
Describing a word that has more than one syllable.
The word 'banana' is multisyllabic because it has three syllables.
Multisyllabic → It is formed from "multi-" (meaning many) and "syllabic" (from Greek "syllabē", meaning a syllable). The word describes something that has many syllables.
Think of 'many' ('multi-') syllables ('syllabic') coming together to form a word.