Definition of mouse-tail:
(n) :
Any small rodent of the genus Mus.
(n) :
(informal) A member of the many small rodent and marsupial species resembling mice, typically having a small body, dark fur, long tail, and nocturnal sleeping pattern.
(n) :
A quiet or shy person.
(n) :
(computing) An input device that is moved over a pad or other flat surface to produce a corresponding movement of a pointer on a graphical display.
(n) :
(computing) A pointer.
(n) :
(boxing) A facial hematoma or black eye.