adjective satellite (s)

• (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)(adj.all)

  Example:
  The lavatory is in use.
  

  Synonym:
  busy, engaged
  

  source: wordnet30
• currently being used(adj.all)

  Example:
  Robots are in use throughout industry.
  

  source: wordnet30