Hirsute officer set about devouring contents of egg (6)
I believe the answer is:
foetus
'egg' is the definition.
The answer and definition can be both animals as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'hirsute officer set about devouring contents of' is the wordplay.
'hirsute officer' becomes 'fo' (I am not sure about this - if you are sure you should believe this answer much more).
'about' indicates anagramming the letters.
'contents of' means to look at the middle letters (I've seen 'content' mean this).
The middle letter of 'devouring' is 'u'.
'set' anagrammed with 'u' makes 'etus'.
'fo'+'etus'='FOETUS'
Can you help me to learn more?
(Other definitions for foetus that I've seen before include "Developed mammalian embryo" , "Unborn child" , "Embryo in later stages" , "Embryo of a mammal" , "Developed embryo in the womb" .)