Two persons in an ongoing relationship; dyadic relationship.
A tensor of order two and rank one.
An element, atom, or radical having a valence of or combining power of two.
A chromosome structure, usually X- or V-shaped, consisting of two condensed sister chromatids joined by a centromere.
A set of two elements treated as one; a pair.
The relationship or interaction itself in reference to a couple.
Any set of two different pitch classes.
A secondary unit of organisation consisting of an aggregate of monads.
An opposite-sex married couple.