Rhyme - the similarity or identity of terminal sound in words. In the most common form, two words rhyme when their accented vowels and all succeeding sounds are identical. This provides pleasing sense impressions and serves as an element of rhythm emphasizing the beat. Rhyme is the commonest and most ancient form of metrical devices.
The term is from the Greek rhuthmos derived from the Latin rhythmus, meaning measured motion or rhythm.
In the Fourteenth Century, rhyme replaced alliteration as the usual patterning device of verse in English. Shakespeare’s Sonnets have every other line rhyming as in “CXXX”:
My mistress’ eyes are nothing like the sun;
Coral is far more red than her lips’ red:
If snow be white, why then her breasts are dun;
If hairs be wire, black wires grow on her head.
lines 1 – 4
see: couplet, poetry