adjective

1. two combined; twofold; duplex
2. having two layers; folded in two
3. having two of one kind; paired; repeated a double consonant
4. being of two kinds; dual a double standard
5. having two meanings; ambiguous
6. twice as much, as many, as large, etc. pay double fare
7. of extra size, value, strength, or quantity
8. designed or made for two a double bed
9. characterized by duplicity; two-faced; deceiving leading a double life
10. having a tone an octave lower double bass
11. Bot. having more than one set of petals

Etymology: ME < OFr < L duplus, lit., twofold (akin to Gr diploos) < duo, two + -plus < IE *plo-, -fold < base *pel-, to fold

adverb

1. to twice the extent or degree; twofold
2. two together; in or by pairs to ride double

noun

1. anything twice as much, as many, or as large as normal
2. a person or thing looking very much like another; duplicate; counterpart
3. a substitute actor or singer
4. a stand-in or substitute, as in films
5. a fold; second ply
6. a sharp turn or shift of direction
7. an evasive trick
8. a game of tennis, handball, etc. with two players on each side
9. ☆ Baseball a hit on which the batter reaches second base
10. Bridge the doubling of an opponent's bid

transitive verb doubled -·bled, doubling -·bling

1. to make double; make twice as much or as many; multiply by two
2. to fold; add another ply to double the bandage
3. to repeat or duplicate
4. to be the double of
5. ☆ Baseball
   1. to put out (the second runner) in executing a double play
   2. to advance (a runner) by hitting a double
6. Bridge to increase the point value or penalty of (an opponent's bid) by saying “double” when it is one's turn to bid
7. Music to supply the upper or lower octave to (another part or voice) double the tenor in brass
8. Naut. to sail around they doubled Cape Horn

intransitive verb

1. to become double; increase twofold
2. to bend or turn sharply backward the animal doubled on its tracks
3. to serve as a double
4. to serve an additional purpose
5. ☆ Informal to double-date
6. ☆ Baseball to hit a double
7. Music to play one or more instruments in addition to one's principal instrument: often with on