What is the definition of rhyme in terms poetry?

Rhyme, in poetry, refers to the repetition of similar or identical sounds at the end of lines. It usually involves the last stressed syllables of the lines. When two or more lines end with similar sounds, they are said to rhyme. For example, in the following lines from Shakespeare's "Sonnet 18", the words "dust" and "just" rhyme:

"So long as men can breathe or eyes can see,

So long lives this, and this gives life to thee."

Here, "dust" and "just" have the same vowel sound ("uh") and the same consonant sound ("st") at the end, creating a rhyme.

Rhyme is often used to create a pleasing and harmonious effect in poetry. It can also be used to emphasize certain words or phrases or to link different parts of the poem. There are different rhyme schemes or patterns, including couplets (two rhyming lines), terza rima (a three-line stanza with the first and third lines rhyming and the middle line rhyming with the first and third lines of the next stanza), and more complex patterns. The use of rhyme can vary greatly depending on the style and preferences of the poet.