subs. (common).1. A personification of sleep: the DUSTMANS coming = you are getting sleepy. Cf., DUST IN THE EYES.
1821. P. EGAN, Tom and Jerry, p. 111. A social glass of wine beguiled an hour or two, till the DUSTMAN made his appearance and gave the hint to Tom and Jerry that it was time to visit their beds.
2. (old).A dead man.
1811. GROSE and CLARKE, Lexicon Balatronicum, s.v.