sonnet n.

1557 (in the title of Surrey's poems), from French sonnet (1540s) or directly from Italian sonetto, literally "little song," from Old Provençal sonet "song," diminutive of son "song, sound," from Latin sonus "sound" (from PIE root *swen- "to sound").

Originally in English and into Elizabethan times, also "any short lyric poem;" the more precise meaning is from Italian, where Petrarch (14c.) developed a scheme of an eight-line stanza (rhymed abba abba) followed by a six-line stanza (cdecde, the Italian sestet, or cdcdcd, the Sicilian sestet).

Wyatt and Surrey were the first to wrestle it in English; Shakespeare developed the English Sonnet (though Petrarch and Dante has written in it) for his rhyme-poor, couplet-loving native tongue: three Sicilian quatrains followed by a heroic couplet (ababcdcdefefgg). Done traditionally, the first stanza sets a situation or problem, and the second comments on it or resolves it.

To have something to say ; to say it under pretty strict limits of form and very strict ones of space ; to say it forcibly ; to say it beautifully ; these are the four great requirements of the poet in general ; but they are never set so clearly, so imperatively, so urgently before any variety of poet as before the sonneteer. [Saintsbury, "History of English Prosody," 1906]