(historical) A turn-out of a carriage and two horses.

(computing, programming) A software development technique, part of extreme programming, in which two programmers work together at a single keyboard, one coding while the other observes and reviews. The roles are often switched at regular intervals.

A pair of twins, one male and one female. / Two siblings, one male and one female.

(chiefly US, colloquial, idiomatic, somewhat vulgar) To be brave; to show some courage, especially in a situation in which one has so far failed to do so.

(American spelling) A national flag and a regimental flag when carried together.

The commission of an ensign in the infantry or a cornet in the cavalry; an ensigncy or cornetcy. / (British spelling) A national flag and a regimental flag when carried together.

Protective eyewear consisting of two lenses set in a flexible frame to fit snugly against the face.

A tool used for cutting thin material, consisting of two crossing blades attached at a pivot point in such a way that the blades slide across each other when the handles are closed

(physics) The simultaneous creation of a particle and its antiparticle.

(chiefly US, colloquial, idiomatic, somewhat vulgar) Synonym of grow a pair