pouched rat vs pocket rat

pouched rat and pocket rat both are nouns.

Word	Noun	Adjective	Verb	Adverb
pouched rat	Yes	No	No	No
pocket rat	Yes	No	No	No

As nouns, pocket rat is a hypernym of pouched rat; that is, pocket rat is a word with a broader meaning than pouched rat:

pouched rat: burrowing rodent of the family Geomyidae having large external cheek pouches; of Central America and southwestern North America
pocket rat: any of various rodents with cheek pouches

pouched rat (noun)	pocket rat (noun)
burrowing rodent of the family Geomyidae having large external cheek pouches; of Central America and southwestern North America	any of various rodents with cheek pouches