Metre (poetry)
In poetry, metre (meter in American English) is the basic rhythmic structure of a verse or lines in verse. Many traditional verse forms prescribe a specific verse metre, or a certain set of metres alternating in a particular order. The study of metres and forms of versification is known as prosody. (Within linguistics, "prosody" is used in a more general sense that includes not only poetical metre but also the rhythmic aspects of prose, whether formal or informal, which vary from language to language, and sometimes between poetic traditions.)
Read more about Metre (poetry): Qualitative Vs. Quantitative Metre, Feet, Half-lines, Caesurae, Metric Variations, History, Dissent