Iambic trimeter

Iambic trimeter is a meter of poetry consisting of three iambic units per line.

In ancient Greek poetry and Latin poetry, iambic trimeter is a quantitative meter, in which a line consists of three iambic metra and each metron consists of two iambi (i.e., a total of six iambic feet per line), though substitutions were common, such as spondees or tribrachs for iambs (see for example Euripides#Chronology). It is the most common metre used for the spoken parts (as opposed to the sung parts) of Ancient Greek tragedy, comedy, and satyr plays. It is also commonly found in iambus or 'blame poetry' though it is not the only meter for that genre.

In the accentual-syllabic verse of English, German, and other languages, iambic trimeter is a meter consisting of three iambs (disyllabic units with rising stress) per line.

The iambic trimeter derives its name from its essential shape, which is three metrical units (hence "trimeter") which are each basically iambic in form. The iambic metron has the following shape (where the "x" is an anceps, the "-" is a longum, and the "u" is a brevis):

The long-short-long structure is known as a cretic, so the basic metrical unit of the iambic trimeter may be said to be the following: anceps-cretic. The trimeter simply repeats this structure three times, with the resulting shape as follows:

Note that, as always, the final syllable can observe the phenomenon of brevis in longo, so it may actually be short or long.

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