| pack rat | n. 1. Any of several bushy-tailed rodents of the genus Neotoma of western North America, especially Neotoma cinerea, which hoard food and other objects in their nests. Syn. -- trade rat, bushytail woodrat, Neotoma cinerea. [ WordNet 1.5 ] 2. A person who habitually saves items, even those unlikely to be useful. [ Informal ] [ PJC ] Variants: packrat |