What is a sonnet?

Webster’s dictionary defines a sonnet as “a fixed verse form of Italian origin consisting of 14 lines that are typically 5-foot iambics rhyming according to a prescribed scheme also: a poem in this pattern.” That’s pretty good, but the part after also doesn’t add anything, does it? It would be better if it said: “a verse form that has 14 lines of rhyming iambic pentameter, or a poem with similarities to this pattern.” Shakespeare’s Sonnets have a lot of variations from the standard sonnet form. The most obvious is the deviation from regular iambic pentameter. Eight percent of lines contain an eleventh syllable (a feminine ending) and 24 percent have at least one foot that is not an iamb. This is a minor point—it just reflects good iambic pentamer (rather than strict “5-foot iambics”). But Sonnet 99 has 15 lines (as does Sonnet 58 of Spencer’s Amoretti). And Sonnet 126 has only 12 lines. Sonnet 126 also has rhyming couplets instead of alternating rhymes. There are 20 other sonnets that don’t follow the usual rhyme scheme. And Sonnet 145 has only 4 feet to a line. Shakespeare also has 8 sonnet pairs and one triplet that must be read together to make coherent poems. Does that mean these poems are not sonnets? I don’t think so. These alternative forms are similar to variations from iambic pentameter—they make the sonnets different without taking away their essential sonnet-ness. That’s one of the things I like about Shakespeare. He knows how and when to break rules. An important concept of the sonnet is one of constraint, adding to the skill required to write a good poem. Sometimes the challenge is to make a complex argument fit into a short space while maintaining the proper rhythm and rhyme. At other times, the challenge is to extend a simple idea to last for an entire poem. The more a poet varies from a particular sonnet standard, the less that sonnet will look like others. But does that matter? If we allow for poetic license, maybe not. So, what is a sonnet? Could it be whatever a poet calls a sonnet?