Definition from Wiktionary, the free dictionary
See also: long tail
longtail (plural longtails)
- Any animal that has an unusually long tail relative to similar species.
- (Bermuda) The white-tailed tropicbird.
- A longtail boat.
- (colloquial, Isle of Man) A rat.
The colloquial usage derives from a relatively modern superstition that it is considered bad luck to use the word "rat".