air passage provided by a retractable device containing intake and exhaust pipes; permits a submarine to stay submerged for extended periods of time
breathing device consisting of a bent tube fitting into a swimmer's mouth and extending above the surface; allows swimmer to breathe while face down in the water
an artifact (or system of artifacts) that is instrumental in accomplishing some end
the quality of being instrumental for some purpose
a subsidiary organ of government created for a special purpose; "are the judicial instrumentalities of local governments adequate?"; "he studied the French instrumentalities for law enforcement"
the act of moving smoothly along a surface while remaining in contact with it; "his slide didn't stop until the bottom of the hill"; "the children lined up for a coast down the snowy slope"
a transparency mounted in a frame; viewed with a slide projector
a small flat rectangular piece of glass on which specimens can be mounted for microscopic study
plaything consisting of a sloping chute down which children can slide
(geology) the descent of a large mass of earth or rocks or snow etc.
move smoothly along a surface; "He slid the money over to the other gambler"
an unstable construction with playing cards; "he built three levels of his cardcastle before it collapsed"
a speculative scheme that depends on unstable factors that the planner cannot control; "his proposal was nothing but a house of cards"; "a real estate bubble"