doubled (Adjective) — Twice as great or many. ex. "the dose is doubled"
doubled (Verb) — Increase twofold. ex. "The population doubled within 50 years"
doubled (Verb) — (baseball) hit a two-base hit.
doubled (Verb) — Bend over or curl up, usually with laughter or pain. ex. "He doubled and vomited violently"
doubled (Verb) — Do double duty; serve two purposes or have two functions. ex. "She doubles as his wife and secretary"
doubled (Verb) — (bridge) make a demand for (a card or suit).
doubled (Verb) — Make, do or perform again. ex. "He could never double his brilliant performance of the magic trick"