| on board(expression, active, busy, occupied, working) |
| on call(adjective, working, available) |
| on the hop(expression, idiom) |
| on the jump(expression, idiom) |
| on the move(expression, idiom) |
| on the payroll(expression, active, busy, occupied, working) |
| on the run(expression, idiom) |
| operating(active, busy, occupied, working, engaged) |
| overloaded(adjective, lively, active, busy, occupied) |
| persevering(adjective, lively, active, busy, occupied) |
| plugging away(expression, active, busy, occupied, working) |
| selected(active, busy, occupied, working, engaged) |
| signed(active, busy, occupied, working, engaged) |
| slaving(adjective, lively, active, busy, occupied) |
| snowed(adjective, lively, active, busy, occupied) |
| swamped(adjective, lively, active, busy, occupied) |
| unavailable(adjective, lively, active, busy, occupied) |
| with a customer(expression, idiom, active, occupied, working) |
| acting |
| awaiting orders |