the.com/couplet

means A pair of consecutive lines of verse, typically rhyming and sharing the same meter, that work as a single unit of thought.

from From French couplet, a diminutive of couple, itself from Latin copula meaning 'link' or 'bond' — the same root that gives us 'copulate' and 'coupling.' The word literally means 'a little pair,' which is exactly what it names: two lines bonded together by rhyme and rhythm into one small, tidy unit of sense.