- Historical a warship with three decks of cannon
- a ship with three decks
- any structure with three levels
- Informal a sandwich made with three slices of bread
- Informal a novel published in three volumes; now, esp., any very lengthy novel
See three-decker in American Heritage Dictionary 4
- A ship having three decks, especially one of a class of sail-powered warships with guns on three decks.
- Something with three levels or layers, as:
a. A three-story apartment building.
b. A sandwich having three slices of bread.
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