Synonyms and related words :
applied, at it, at work, busy, chartered, engaged, exercised, exerted, full of business, hard at it, hard at work, hired, hireling, in harness, leased, let, mercenary, occupied, on duty, on the go, on the hop, on the job, on the jump, on the move, on the run, paid, rented, secondhand, subleased, sublet, tied up, used, working