| Noun | 1. | tail fin - a stabilizer that is part of the vertical tail structure of an airplanestabilizer - airfoil consisting of a device for stabilizing an aircraft vertical tail - the vertical airfoil in the tail assembly of an aircraft | |
| 2. | tail fin - one of a pair of decorations projecting above the rear fenders of an automobile | |
| 3. | tail fin - the tail of fishes and some other aquatic vertebratesfin - organ of locomotion and balance in fishes and some other aquatic animals heterocercal fin - tail fin with unequal lobes in which the vertebral column turns upward into the larger lobe as in sharks homocercal fin - symmetrical tail fin extending beyond the end of the vertebral column as in most bony fishes fish - any of various mostly cold-blooded aquatic vertebrates usually having scales and breathing through gills; "the shark is a large fish"; "in the livingroom there was a tank of colorful fish" | |