Collected together in animal's den, reportedly (3)
I believe the answer is:
set
'collected together in animal's den' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe there's a link between them I don't understand?
'reportedly' is the wordplay.
I cannot really understand how this works, but
'reportedly' could be 'e' (I've seen this in other clues) and 'e' is present in the answer.
The remaining letters 'st' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for set that I've seen before include "Prepared" , "Become fixed or solid" , "See 16 Down" , "Determined or congealed" , "group usually found together" .)