in use meaning and definition

IN USE adjective

Definition of in use (adjective)

1. (of facilities such as telephones or lavatories) unavailable for use by anyone else or indicating unavailability; (`engaged' is a British term for a busy telephone line)
   • "her line is busy"; "receptionists' telephones are always engaged"; "the lavatory is in use"; "kept getting a busy signal"
   • synonyms: busy, engaged
2. currently being used
   • "robots are in use throughout industry"