A word that joins two words as a pair?

There isn't one specific word that universally joins two words as a pair. The best way to describe this depends on the context:

General usage:

* And: This is the most common conjunction for joining two things together as a pair.

* Both...and: This emphasizes that both items are included as a pair.

* Together: This highlights the combined nature of the pair.

* Pair: This noun itself can be used to describe the two things as a pair.

More specific usages:

* Couplet: Used for two lines of poetry that rhyme.

* Duo: Used for a pair of performers or musicians.

* Couple: Used for two people in a romantic relationship.

* Twin: Used for two people born at the same time to the same mother.

Example:

* General: "We had pizza and soda for dinner."

* Emphasizing both: "We ate *both* pizza *and* soda."

* Together: "We enjoyed pizza and soda *together*."

* Pair: "We ordered a *pair* of pizzas."

* Specific: "The singer performed a duet with her partner."

Let me know if you have a specific example in mind, and I can help you find the most appropriate word!