Synonyms to on the bum

on the go, astir, at it, at work, busy, employed, en route, engaged, full of business, hard at it, hard at work, in harness, in motion, in transit, occupied, on duty, on the gad, on the hop, on the job, on the jump, on the move, on the road, on the run, on the tramp, on the wing, tied up, under sail, under way, working, amain, apace, at once, by forced marches, cursorily, expeditiously, feverishly, furiously, hand over fist, hastily, helter-skelter, hotfoot, hurriedly, hurry-scurry, immediately, in passing, instantly, o