couplet

noun

1. A set of two things, particularly.
2. (abbreviation, alt-of, ellipsis)A set of two things, particularly.

   “At the session, vivid displays of cultural elements related to the Spring Festival, such as couplets, dragon dance, and Chinese knots, accompanied by melodies full of Spring Festival flavor, brought the festival's rich traditions to life.”

   “As residents across China are handwriting festive couplets and the character fu (fortune) to ring in the Chinese New Year, new content and creative designs have breathed new life into the tradition as topics related to the ingenuity on display have also gone trending on social media recently.”

3. A set of two things, particularly.

   “5th Street is one-way west only and 6th Street is one-way east only. Together, they form a couplet in Downtown Los Angeles.”

4. A set of two things, particularly.

   “The dichotomous keys are constructed so that each couplet presents a set of alternative choices.”

   “As long as the correct statement of each couplet is chosen, and the unknown organism is included in the key, a confident identification is usually achieved.”