absorbed, absorbed in, abstracted, at it, at work, buried in, buried in thought, busy, caught up in, colonized, contemplating, contemplative, devoted, devoted to, empeopled, employed, engaged, engaged in thought, engrossed, engrossed in, engrossed in thought, full of business, hard at it, hard at work, immersed in, immersed in thought, in harness, inhabited, intent, intent on, introspective, involved, lost in, lost in thought, meditating, meditative, monomaniacal, monopolized, obsessed, on duty, on the go, on the hop, on the job, on the jump, on the move, on the run, peopled, populated, populous, preoccupied, rapt, settled, single-minded, studious, studying, submerged in, swept up, taken up with, tenanted, tied up, totally absorbed, working, wrapped in, wrapped in thought, wrapped up in