Word Study
flippers
CIDE DICTIONARY
flippers, n. [By analogy with flipper[W13(1)], the limb of an aquatic animal used for locomotion].
A type of shoe with a paddle-like front extending well beyond the end of the toe, used an aid in swimming (especially underwater).
"They are typically of rubber-like material, and are not worn when walking on land." [WordNet 1.5]
For further exploring for "flippers" in Webster Dictionary Online