The pattern established by the arrangement of rhymes in a stanza or poem, generally described by using letters of the alphabet to denote the recurrence of rhyming lines, such as the ababbcc of the Rhyme Royal stanza form.
Sidelight: The opening stanza of Wordsworth's "I Wandered Lonely as a Cloud," with end rhymes of the words, cloud-hills-crowd-daffodils-trees-breeze, is described as having a rhyme scheme of ababcc; the two quatrains of the poem, "La Tour Eiffel," with end words of form-warm-storm-insouciance and earth-mirth-birth-France, have an interlocking or chain rhyme scheme of aaab cccb.
Sidelight: Capital letters in the alphabetic rhyme scheme are used for the repeating lines of a refrain; the letters x and y indicate unrhymed lines.
Sidelight: In quatrains, the popular rhyme scheme of abab, as in Wordsworth's "She Dwelt Among the Untrodden Ways," is called alternate rhyme or cross rhyme. Tennyson used an abba scheme, often called envelope rhyme, for In Memoriam. The rhyme scheme of Fitzgerald's The Rubáiyát of Omar Khayyám is aaxa.

This definition is in context to Poetry. See more contextual defintions for Rhyme Scheme.