(informal) An imaginary medicine taken when excessively anxious or upset about a trivial matter.

A drug, such as mifepristone (Mifegyne), used to terminate a pregnancy in its earliest stage.

(US) Any of very many terrestrial crustaceans, of the family Armadillidiidae, a subgroup of the woodlice, that can roll themselves up into a protective ball.

(pharmacology) A pill or tablet having a soporific effect.

(figuratively) Ellipsis of bitter pill to swallow. / Used other than figuratively or idiomatically: see bitter, pill.

plural of pill bug

(Britain, slang) A tablet of the drug ecstasy.

(idiomatic, medicine) A medication, usually prescribed by a physician, which the patient is to carry with him or her, and which is to be used only under certain conditions.

(business) Any strategy designed to produce negative results for an entity carrying out a takeover.

(humorous) A hypothetical pill that makes those who take it silly.