WordNet sense 1 (a stand-in for movie stars to perform dangerous stunts):

stunt man, stunt woman

WordNet sense 2 (someone who closely resembles a famous person (especially an actor)):

image, look-alike

WordNet sense 3 (having more than one decidedly dissimilar aspects or qualities):

dual, threefold, treble, twofold, two-fold, three-fold

WordNet sense 4 (consisting of or involving two parts or components usually in pairs):

duple

WordNet sense 5 (twice as great or many):

doubled

WordNet sense 6 (having or involving or consisting of more than one part or entity or individual):

multiple

WordNet sense 7 (bend over or curl up, usually with laughter or pain):

double over, double up

WordNet sense 8 (make or do or perform again):

duplicate, repeat, replicate, reduplicate, duplicate

WordNet sense 9 (used of homologous chromosomes associated in pairs in synapsis):

bivalent

WordNet sense 10 (above average in size or number or quantity or magnitude or extent):

big, large

WordNet sense 11 (having two meanings with intent to deceive):

forked

WordNet sense 12 (open to two or more interpretations; or of uncertain nature or significance; or (often) intended to mislead):

equivocal

WordNet sense 13 (raising the stakes in a card game by a factor of 2):

doubling

WordNet sense 14 (a base hit on which the batter stops safely at second base):

two-bagger, two-baser, two-base hit

WordNet sense 15 (to double the degree):

doubly, twice