means The matching of similar sounds, usually at the ends of words or lines, especially in poetry and song.

from From Old French 'rime,' meaning verse or meter, which traces back to Latin 'rhythmus' and Greek 'rhythmos' (measured flow). The 'h' is a later affectation: scholars added it to make the word look more like Greek 'rhythm,' even though the two had drifted apart in meaning. So the spelling itself is a bit of borrowed prestige — a word dressing up to seem more classical than it needed to be.