(of facilities such as telephones or lavatories) unavailable for use by anyone else or indicating unavailability; (`engaged' is a British term for a busytelephone line); "her line is busy"; "receptionists' telephones are always engaged"; "the lavatory is in use"; "kept getting a busy signal"
(used of toothedparts or gears) interlocked and interacting; "the gears are engaged"; "meshed gears"; "intermeshed twin rotors"