twice as large, heavy, strong, etc.; twofold in size, amount, number, extent, etc.

a double portion; a new house double the size of the old one.

composed of two like parts or members; twofold in form; paired

double doors; a double sink.

of, pertaining to, or suitable for two persons

a double room.

twofold in character, meaning, or conduct; dual or ambiguous

a double interpretation.

deceitful; hypocritical; insincere.

(of musical instruments) producing a tone an octave lower than the notes indicate.

duple, as time or rhythm.

folded in two; having one half folded over the other.

(of a bed or bedclothes) full-size

a double blanket.

Botany . (of flowers) having many more than the normal number of petals

double petunias; double hollyhocks.

anything that is twofold in size or amount or twice the usual size, quantity, strength, etc.

a duplicate or counterpart; something exactly or closely resembling another

This dress is the double of that. He is the double of his cousin.

Also called double room. a type of hotel accommodation with two beds, or sometimes a double bed, for occupancy by two persons. Compare twin ( def. 4 ) .

a fold or plait.

an alcoholic drink containing twice the usual amount of alcohol.

a sudden backward turn or bend, as of a fox on the run in fox hunting; reversal.

a trick or artifice, as of argument in a formal debate.

a substitute actor or singer ready to take another's place; understudy.

Movies, Television . a substitute who performs feats or actions too hazardous or difficult for a star.

Baseball . two-base hit.

Military . double time.

doubles, ( used with a singular verb ) a game or match in which there are two players on each side, as in tennis.

(in bridge or other card games)

a challenge by an opponent that the declarer cannot fulfill the designated contract, increasing the points to be won or lost.

a hand that warrants such a challenge.

Bridge . a conventional bid informing one's partner that a player's hand is of a certain strength.

Bowling . two strikes in succession

He needed a double in the tenth frame to win.

daily double.

any of certain feasts in the Roman Catholic Church, marked by a doubled antiphon and taking precedence over lesser feasts.

Music Rare . a variation.

a former coin of France, the sixth part of a sol, issued in silver in the 14th century, later made of copper.

to make double or twice as great; to add an equal amount to

The baby doubled its weight in a year.

to bend or fold with or as with one part over another (often fol. by over, up, back, etc.)

Double the edge over before sewing.

to clench

He doubled his fists.

to be or have twice as much as

Income doubled expenditure.

Nautical .

to sail around (a projecting area of land)

to double Cape Horn.

to add a new layer of planking or ceiling to (an old wooden hull).

to pair; couple

The players were doubled for the tournament.

Music . to reduplicate by means of a tone in another part, either at the unison or at an octave above or below.

(in bridge and other card games)

to challenge (the bid of an opponent) by making a call that increases the value of tricks to be won or lost.

to challenge the bid of (an opponent)

He doubled me into game.

Baseball .

to cause the advance of (a base runner) by a two-base hit

He doubled him to third.

to cause (a run) to be scored by a two-base hit (often fol. by in )

He doubled in the winning run.

to put out (a base runner) as the second out of a double play (often fol. by up ).

to become double

My money doubled in three years.

to bend or fold (often fol. by up or over )

to double over with pain.

to turn back on a course or reverse direction (often fol. by back )

He doubled back by another road and surprised us.

Military . to march at the double-time pace.

to serve in two capacities or in an additional capacity

She doubles as producer and director.

to act as a double in a play, motion picture, or the like.

Music . to play an instrument besides one's regular instrument (usually followed by on )

The saxophonist doubles on drums.

(in bridge and other card games) to double the bid of an opponent.

Baseball . to make a two-base hit.

to double-date.

to twice the amount, number, extent, etc.; twofold; doubly.

two together

There are only a few beds, so some of the children will have to sleep double for the night.

double up,

to share quarters planned for only one person or family

Because of the room shortage, we had to double up.

to bend over, as from pain

He doubled up in agony.

at the double

British Informal . on the double.

double in brass

Informal . to serve in two capacities; be able to do work different from one's own

It is a small firm, and everyone doubles in brass when emergencies arise.

double or nothing, a bet having as its outcome either the doubling of a previous loss or debt or the canceling of that loss or debt. Also

double or quits.

on the double

Informal .

without delay; rapidly

The fire engines came on the double.

in double time, as marching troops.