What is the meaning of the word "double"?

Definitions:

a base hit on which the batter stops safely at second base noun
- The batter hit a double to deep centerfield.
a quantity that is twice as great as another noun
- 36 is the double of 18
a stand-in for movie stars to perform dangerous stunts noun
- Their first job in Hollywood was as a double for the movie star.
bend over or curl up, usually with laughter or pain verb
- The drunk person doubled over and vomited violently.
consisting of or involving two parts or components usually in pairs adjective
- an egg with a double yolk
downward and forward adverb
- I was bent double with pain.
having more than one decidedly dissimilar aspects or qualities adjective
- a double (or dual) role for an actor
having two meanings with intent to deceive adjective
- a sly double meaning
increase twofold verb
- The population doubled within 50 years
large enough for two adjective
- a double bed
raising the stakes in a card game by a factor of 2 noun
- I decided their double was a bluff.
someone who closely resembles a famous person, especially an actor noun
- I could be Arnold Schwarzenegger's double.
twice as great or many adjective
- ate a double portion
two together adverb
- some people sleep better double
used of flowers having more than the usual number of petals in crowded or overlapping arrangements adjective
- double chrysanthemums have many rows of petals and are usually spherical or hemispherical