| busy(adverb, occupied, room, telephone) |
| occupied(adjective, active, full, involved, busy) |
| employed(adjective, active, full, involved, busy) |
| unavailable(adjective, full, involved, busy, occupied) |
| engaged(adjective, active, full, involved, busy) |
| taken(adjective, full, busy, occupied, engaged) |
| used |
| in force(expression, adjective, active, effective, operative) |
| in operation(expression, adjective, active, effective, operative) |
| rampant(adjective, present, new, common, familiar) |
| regnant(adjective, present, new, common, familiar) |
| rife(adjective, present, new, common, familiar) |
| absorbed(adjective, full, involved, occupied, working) |
| accepted(adjective, present, common, familiar, modern) |
| accessible(adjective, common, familiar, standard, current) |
| accustomed(adjective, present, common, modern, general) |
| active(adjective, busy, alive, working, operative) |
| afoot(adjective, present, modern, general, prevailing) |
| at work(expression, adjective, active, full, involved) |
| circulating(adjective, present, modern, general, prevailing) |