Lockdown |ˈlɒkdaʊn| nounN. Amer. the confining of prisoners to their cells, typically in order to regain control during a riot. the lockdown has been in effect since October 1983. • a state of isolation or restricted access instituted as a security measure: the university is on lockdown and nobody has been able to leave. <> Curfew |ˈkəːfjuː| noun a regulation requiring people to remain indoors between specified hours, typically at night: a dusk-to-dawn curfew | [ mass noun ] : the whole area was immediately placed under curfew. • the hour designated as the beginning of a curfew. [ mass noun ] : to be abroad after curfew without permission was to risk punishment. • the daily signal indicating the beginning of a curfew: they had to return before the curfew sounded.