highly significant or important especially bringing about or marking the beginning of a new development or era; "epochal decisions made by Roosevelt and Churchill"; "an epoch-making discovery"
(computer science) electronic equipment connected by cable to the CPU of a computer; "disk drives and printers are important peripherals"
on or near an edge or constituting an outer boundary; the outer area; "Russia's peripheral provinces"; "peripheral suburbs"
related to the key issue but not of central importance; "a peripheral interest"; "energy is far from a peripheral issue in the economy"; "peripheral issues"
the act of containing; keeping something from spreading; "the containment of the AIDS epidemic"; "the containment of the rebellion"
(physics) a system designed to prevent the accidental release of radioactive material from a reactor
a policy of creating strategic alliances in order to check the expansion of a hostile power or ideology or to force it to negotiate peacefully; "containment of communist expansion was a central principle of United States' foreign policy from 1947 to the 1975"