club sandwich

noun
1.
a sandwich, typically on three slices of toast, interlaid with pieces of cold chicken or turkey and bacon or ham and containing lettuce, tomato, mayonnaise, etc.
Also called three-decker, triple-decker.
Origin
1900-05, Americanism
British Dictionary definitions for club sandwich

club sandwich

noun
1.
a sandwich consisting of three or more slices of toast or bread with a filling