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tail fin also tail·fin

(tālfĭn′)

1. A fin at the posterior part of the body of a fish, crustacean, whale, or other aquatic animal.

2. An ornamental projection shaped like a fin on the rear fender of an automobile. Also called fin¹.

3. A fin at the tail end of an aerodynamic or hydrodynamic object such as an airplane or surfboard, used to provide directional control or stability.

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tail fin

1959 Cadillac Fleetwood Sixty Special

Indo-European & Semitic Roots Appendices

Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:

Indo-European Roots

Semitic Roots

The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.

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