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
the service (electric power or water or transportation) provided by a public utility; "the cost of utilities never decreases"; "all the utilities were lost after the hurricane"
a facility composed of one or more pieces of equipment connected to or part of a structure and designed to provide a service such as heat or electricity or water or sewage disposal; "the price of the house included all utilities"
the quality of being of practical use
a company that performs a public service; subject to government regulation
(economics) a measure that is to be maximized in any situation involving choice
a score in American football; a player is tackled behind his own goal line
a safe place; "He ran to safety"
the state of being certain that adverse effects will not be caused by some agent under defined conditions; "insure the safety of the children"; "the reciprocal of safety is risk"
line thrown from a vessel that people can cling to in order to save themselves from drowning
line that raises or lowers a deep-sea diver
support that enables people to survive or to continue doing something (often by providing an essential connection); "the airlift provided a lifeline for Berlin"; "she offered me a lifeline in my time of grief"
having the function of uniting a group of similar things; "the Democratic Party is an umbrella for many liberal groups"; "under the umbrella of capitalism"
a formation of military planes maintained over ground operations or targets; "an air umbrella over England"
a lightweight handheld collapsible canopy
covering or applying simultaneously to a number of similar items or elements or groups; "an umbrella organization"; "umbrella insurance coverage"