Definition of "sandwichman"

"There came along in the gutter a sandwich-man. […] Now I read what was on his boards. […] "

1899, Harold Frederic, The Marketplace

INDORSE To write on the back of; the best indorsed man in town being the Sandwich-Man.

1904, Gideon Wurdz, The Foolish Dictionary

Certainly it amounted to a continual advertisement for him; an infinitely more effective advertisement than, for instance, a sandwichman at eighteen-pence a day, and costing no more, even with the licence and the shoeing.

1911, Arnold Bennett, The Card