By having the animal skirt the chasm (5)
I believe the answer is:
abyss
'the chasm' is the definition.
(abyss is a kind of chasm)
'by having the animal skirt' is the wordplay.
I cannot quite understand how this works, but
'by' is within the answer.
'animal' could be 'ass' (term for a donkey) and 'ass' is found within the remaining letters.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for abyss that I've seen before include "Fathomless pit" , "Hell; hole" , "Seemingly bottomless chasm" , "Very large and deep chasm" , "crevasse" .)