IPA: /ʌnˈrɪðmɪk/
KK: /ʌnˈrɪðmɪk/
Not having a regular beat or pattern in music or movement.
The dancer's movements were so unrhythmic that it was hard to follow the music.
Unrhythmic → It is formed from "un-" (meaning not) and "rhythmic" (from Greek "rhythmos", meaning measured flow or movement). The word "unrhythmic" means not having a regular or measured flow or rhythm.
Think of 'not' ('un-') having a 'measured flow' ('rhythmic') — that's why unrhythmic means lacking rhythm.