What does double mean?
"Double" is one of English's most versatile words, functioning as an adjective, adverb, noun, and verb, all built around a single core idea: two. As an adjective, it describes something twice the usual size, amount, or intensity, or something made up of two matching parts — a double bed, a double portion, a double agent. As an adverb, it signals twofold action, as in paying double. The noun covers a wide range: a look-alike or stand-in for a performer, a baseball hit reaching second base, a strong drink made with twice the spirit, or a game of tennis played by pairs. As a verb, it means to make or become twice as large, common in business contexts such as profits doubling in a year. Derived from Latin via Old French, it carries connotations of both abundance and deception, seen in phrases like 'double standards' and 'double-dealing.' Its ubiquity makes it essential vocabulary.
Something twice the size or amount of a unit; a person who looks exactly like another, especially one standing in for an actor; a baseball hit that allows the batter to reach second base.
"The actor's double performed all the dangerous driving scenes."
To make or become twice as much or as many.
"The bakery doubled its output ahead of the holiday season."
Consisting of two matching or paired parts, or twice the usual amount, size, or strength.
"They booked a room with a double bed."
Twice as much, or serving two purposes at once.
"The sofa doubles as a guest bed."
Most often used in the plural for the game of tennis/badminton with two players per side, or for multiple look-alikes.
"She won the mixed doubles championship twice."
"Double" and "doubt" come from the same Latin root meaning two — because a doubter is literally caught between two minds.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of double
Double comes from Latin 'duplus,' meaning twofold, formed from 'duo' (two) plus the suffix '-plus' (fold), which also gives us duple, duplicate, and duplicity. It entered Middle English through Old French 'duble' around the thirteenth century. Interestingly, the same Latin root underlies 'doubt' and 'dubious,' reflecting the idea of being caught between two possibilities.
Related word forms
How double is actually used
Highly versatile across registers, appearing everywhere from casual speech ('double-check it') to formal financial reporting ('revenues doubled year over year'). In gambling and games, 'to double' means to raise stakes twofold. The phrase 'double down,' originally from blackjack, has become common idiomatically for persisting in a position despite criticism.
Easily confused with double
A duel is a formal fight between two people, whereas double means twice as much or twofold — they sound similar but share no meaning.