1. Movement or variation characterized by the regular recurrence or alternation of different quantities or conditions: the rhythm of the tides.
2. The patterned, recurring alternations of contrasting elements of sound or speech.
3. Music.
   1. The pattern of musical movement through time.
   2. A specific kind of such a pattern, formed by a series of notes differing in duration and stress: a waltz rhythm.
   3. A group of instruments supplying the rhythm in a band.
4. 1. The pattern or flow of sound created by the arrangement of stressed and unstressed syllables in accentual verse or of long and short syllables in quantitative verse.
   2. The similar but less formal sequence of sounds in prose.
   3. A specific kind of metrical pattern or flow: iambic rhythm.
5. 1. The sense of temporal development created in a work of literature or a film by the arrangement of formal elements such as the length of scenes, the nature and amount of dialogue, or the repetition of motifs.
   2. A regular or harmonious pattern created by lines, forms, and colors in painting, sculpture, and other visual arts.
6. The pattern of development produced in a literary or dramatic work by repetition of elements such as words, phrases, incidents, themes, images, and symbols.
7. Procedure or routine characterized by regularly recurring elements, activities, or factors: the rhythm of civilization; the rhythm of the lengthy negotiations.

[Latin rhythmus, from Greek rhuthmos.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.