nonrhythmic

Nonrhythmic is an adjective describing the absence of rhythm: the lack of a regular, repeating pattern of timing, accent, or pulse in a sound, movement, or sequence. The term is formed from non- + rhythmic, and it is most often used descriptively rather than as a formal technical term. Its etymology traces to the Greek rhythm with the negating prefix non-.

In music, nonrhythmic passages do not adhere to a steady meter or pulse. They may occur in free or experimental styles where tempo, accent, and phrasing are irregular or improvised. Nonrhythmic writing or performance can be intentional, emphasizing freedom from a fixed beat, or it may result from expressive aims that disrupt conventional timing. It is related to, but distinct from, terms such as arrhythmic or nonmetric, which describe specific departures from metric structure.

In other contexts, nonrhythmic can describe patterns that lack stable timing in speech, movement, or data sequences. In linguistics or poetry, the term might be used informally to indicate nonmetrical cadence, though more precise terms such as free verse or irregular prosody are often preferred. In data analysis or time-series contexts, nonrhythmic patterns do not display clear periodic components, and methods such as spectral analysis may reveal a lack of dominant frequencies.

Overall, nonrhythmic conveys the idea of irregularity in timing rather than a particular style or genre, and its use varies across disciplines. See also rhythm, arrhythmia, free verse, and nonmetric.