double
//ˈdʌb.əl//
Adjective
Consisting of two equal, identical, or similar parts or things
The room has double doors.
Twice as much in size, strength, number, or amount
The new room is double the size of the old one.
Designed for two people
We booked a double room at the hotel.
Verb
To become twice as much or as many; to multiply by two
The population doubled in ten years.
To fold or bend something over on itself
She doubled the blanket and put it on the bed.
To serve a second purpose or function in addition to the first
The spare bedroom doubles as a home office.
Noun
A quantity that is twice as much as another
Ten is the double of five.
A person who looks exactly like another person
She met her double at the party and couldn't believe how similar they looked.
A room in a hotel for two people, or a bed designed for two people
I'd like to book a double for two nights.
A game of tennis or other sport with two players on each side
We played a doubles match in tennis yesterday.
Adverb
In a way that involves two things or twice the amount
I had to pay double for the last-minute ticket.