Rodent valued for its fur (5)
'rodent valued for its fur' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for muskrat that I've seen before include "Beaver-like American rodent" , "Rodent valued for its fur" , "Vole-like animal" , "Large aquatic rodent" , "North American amphibious rodent" .)
(Other definitions for coypu that I've seen before include "aquatic mammal" , "S. American "beaver"" , "Large semiaquatic rodent" , "Large South American beaver-like rodent" , "Large South American aquatic rodent" .)