(engineering, archaic) A device for saving power in stopping and starting a railroad car, by means of a heavy flywheel.

Alternative spelling of whoop-de-doo

(pathology) A reduced level of adiponectin in the bloodstream, especially as a risk-factor in diabetes

(Britain, slang) Synonym of bottom: a homosexual man who is penetrated or prefers to be penetrated during anal sex. / Used other than figuratively or idiomatically: see shirt, lifter.