means A fourteen-line poem in a fixed rhyme scheme and meter, traditionally meditating on love or some single sustained idea.

from From the Italian sonetto, meaning 'little song,' a diminutive of suono, 'sound' — itself from the Latin sonus. So the word carries its modesty in its name: not a song but a small one, a sound shrunk to fit a frame. The form was perfected in 13th-century Italy and made famous by Petrarch, then carried into English by Renaissance poets who reshaped it into the rhyme scheme we now call Shakespearean.