1. past tense and past participle of double; made twice as much or twice as many
2. folded something over on itself
3. served two purposes or functions at the same time

1. made twice as much, twice as large, or having two of something

Examples

• The company doubled its profits this year.
• She doubled the recipe to feed more people.
• He doubled the paper and put it in his pocket.
• The actor doubled as the director for this film.
• They lived in a doubled house with two separate entrances.
• The doubled fabric made the curtains much thicker.
• Sales have doubled since the new marketing campaign began.