a set of two corresponding things; a pair.

a pair of opposites.

the feeling of being dual or separate from; dualism.

a physical combat between only two persons.

lack of certainty; uncertainty; doubt.

a disputing; a dispute; heated argument.

a discussion between two that is supposed to be kept from the knowledge of others.

(gram.) a compound word in which both the words combined without lowering the importance of either of them.