To make into a sandwich or something of like arrangement; insert between two other things: as, to sandwich a slice of ham between two slices of bread; to sandwich a picture between two pieces of pasteboard.
noun.
Two thin slices of bread, plain or buttered, with some savory article of food, as sliced or potted meat, fish, or fowl, placed between: as, a ham sandwich; a cheese sandwich.
noun.
Hence Anything resembling or suggesting a sandwich; something placed between two other like things, as a man carrying two advertising-boards, one before and one behind.