a book of blank pages with pockets or envelopes; for organizing photographs or stamp collections etc
one or more recordings issued together; originally released on 12-inch phonograph records (usually with attractive record covers) and later on cassette audio tape and compact disc
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
being in effect or operation; "de facto apartheid is still operational even in the `new' African nations"- Leslie Marmon Silko; "bus service is in operation during the emergency"; "the company had several operating divisions"
of or intended for or involved in military operations
pertaining to a process or series of actions for achieving a result; "operational difficulties"; "they assumed their operational positions"
(American football) a play in which a defensive player is allowed to cross the line of scrimmage and then blocked off as the runner goes through the place the lineman vacated