Meaning of IN USE(P)

WordNet Dictionary
	Definition:		[adj]  (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, occupied