arrhythmic (adj.) Look up arrhythmic at Dictionary.com
"without rhythm," 1844 (arhythmic), in relation to musical sensibility, Modern Latin, from Greek arrhythmos "irregular, unrhythmical, without measure," from a- "not" (see a- (3)) + rhythmos "measured flow or movement, rhythm; proportion, symmetry" (see rhythm). Related: Arrhythmically.