Etymology

Adjective

1. Made up of two matching or complementary elements

   The closet has double doors.

2. Twice the quantity

   Give me a double serving of mashed potatoes.

3. Of a family relationship, related on both the maternal and paternal sides of a family

   He's my double cousin as my mother's sister married my father's brother.

4. Designed for two users.

   a double room

5. Folded in two; composed of two layers.
6. Stooping; bent over.
7. Having two aspects; ambiguous.

   a double meaning

8. False, deceitful, or hypocritical.

   a double life

9. Of flowers, having more than the normal number of petals.
10. Of an instrument, sounding an octave lower.

    a double bass

11. Of time, twice as fast.

Adverb

1. Twice over; twofold.
2. Two together; two at a time. (esp. in see double)

Noun

1. Twice the number, amount, size, etc.
2. A person who resembles and stands in for another person, often for safety purposes

   Saddam Hussein was rumored to have many doubles.

3. A drink with two portions of alcohol

   On second thought, make that a double.

4. A two-base hit

   The catcher hit a double to lead off the ninth.

5. A ghostly apparition of a living person; doppelgänger.
6. A sharp turn, esp. a return on one's own tracks.
7. A call that increases certain scoring points if the last preceding bid becomes the contract.
8. A strike in which the object ball is struck so as to make it rebound against the cushion to an opposite pocket.
9. A bet on two horses in different races in which any winnings from the first race are placed on the horse in the later race.
10. The narrow outermost ring on a dartboard.
11. A hit on this ring.
12. Short form of double-precision floating-point number.

    The sin function returns a double.

Verb

1. To multiply by two

   The company doubled their earnings per share over last quarter.

2. To fold over so as to make two folds

   To make a pleat, double the material at the waist.

3. To get a two-base hit

   The batter doubled into the corner.

4. (sometimes foll. by up) To clench (a fist).
5. (often foll. by together or up) To join or couple.
6. To repeat exactly; copy.
7. To play two parts or serve two roles.
8. To turn sharply; following a winding course.
9. To sail around (a headland or other point).
   • 1719- Daniel Defoe, Robinson Crusoe

     ...though the island itself was not very large...I found a great ledge of rocks lie out about two leagues into the sea...so that I was obliged to go a great way out to sea to double the point.

10. To duplicate (a part) either in unison or at the octave above or below it.
11. To be capable of performing (upon an additional instrument).
12. To make a call that will double certain scoring points if the preceding bid becomes the contract.
13. To cause (a ball) to rebound from a cushion before entering the pocket.
14. (foll. by for) To act as substitute.
15. To go or march at twice the normal speed.
16. To increase by 100%, to become twice as large in size.

    Our earnings have doubled in the last year.

Adjective

1. Double.

   Il s'agit d'une phrase à double sens.

Noun

1. Double.

   Je n'en avais pas assez, alors j'en acheté le double.