Slow-moving mammal (5)
I believe the answer is:
sloth
'slow-moving mammal' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for sloth that I've seen before include "edentate" , "Arboreal creature" , "one of a deadly collection" , "Inertia" , "Lethargy" .)