Skin of cat, maybe, absorbing learner (4)
I believe the answer is:
pelt
'skin' is the definition.
(an animal's skin)
'cat maybe absorbing learner' is the wordplay.
'cat maybe' becomes 'pet' (cats are kept as pets).
'absorbing' indicates putting letters inside.
'learner' becomes 'l' (as in a learner driver with L-plates on their car).
'pet' going around 'l' is 'PELT'.
'of' acts as a link.
(Other definitions for pelt that I've seen before include "Hide; rain" , "fall hard" , "Skin of a fur-bearing mammal" , "Skin, hide" , "what rain might do" .)