Pack animal's tendon problem (8)
I believe the answer is:
ganglion
'tendon problem' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'pack animal's' is the wordplay.
'pack' becomes 'gang' (synonyms).
'animal' becomes 'lion' (I've seen this before).
'gang'+'lion'='GANGLION'
Can you help me to learn more?
(Other definitions for ganglion that I've seen before include "Collection of nerve cells" , "Swelling" , "that shows a bit of nerve" , "a group of nerve cells radiating fibres" , "concentration of strength" .)