(electrical engineering) A device or system that almost instantaneously provides emergency power in the case that main power fails.

(set theory) The axiom that the power set of any set exists and is a valid set, which appears in the standard axiomatisation of set theory, ZFC.

infusorial earth used for polishing

(electricity) The storing of generated electrical power as a gaseous substance, usually by electrolyzing water into hydrogen and oxygen gases, and carbonizing the hydrogen into methane gas

(now historical) A loose dressing gown worn while the hair or wig was being powdered.

plural of powdering gown

plural of power move

A type of dance move in b-boying, involving speed, momentum, and acrobatic elements. / (figuratively) An aggressive action taken to demonstrate power and dominance.

(historical) A cosmetic powder for dusting the hair, to remove grease etc.

(historical) A cosmetic, made from crushed pearls, for improving the appearance of the skin.