Meter

Definition: a recurring pattern of stressed (accented, or long) and unstressed (unaccented, or short) syllables in lines of a set length.

Example:

That time | of year | thou mayst | in me | behold

Significance: Meter in poetry and verse lets the reader/speaker understand how to read it, and the flow of the poem. The rhythm of the poem is also really related to the meter. This makes it easier to see the pattern of the words.