The Bedford Glossary of Critical and Literary Terms - Ross Murfin 2018
Closed couplet
Closed couplet: Two successive lines of rhyming verse whose meaning is grammatically or logically complete, forming a statement that can stand meaningfully on its own.
EXAMPLES: John Dryden’s “Epigram on Milton” (1688), a poem about three poets (Homer of Greece, Virgil of Rome, and John Milton of England), is suggestively composed of three closed couplets (the last of which involves an eye rhyme):
Three poets, in three distant ages born,
Greece, Italy, and England did adorn.
The first in loftiness of thought surpassed,
The next in majesty, in both the last:
The force of Nature could no farther go;
To make a third, she joined the former two.