couplet

/ˈkʌp.lət/noun
Middle School
1

A pair of lines, typically with rhyming end words.

2

Ellipsis of antithetical couplet, Chinese couplet, or duilian couplet (“duilian”).

3

A pair of one-way streets which carry opposing directions of traffic through gridded urban areas.

4

A pair of two mutually exclusive choices in a dichotomous key.