cheville

1. (poetry) A word or phrase whose only function is to make a sentence metrically balanced.Examples: "The genius of prose rejects the cheville no less emphatically than the laws of verse; and the cheville, I should perhaps explain to some of my readers, is any meaningless or very watered phrase employed to strike a balance in the sound."; "The practice of using chevilles was very common in old Irish poetry, and a bad practice it was; for many a good poem is quite spoiled by the constant and wearisome recurrence of these chevilles."