Fierce beast better groomed by mother (3-5)
I believe the answer is:
man-eater
'fierce beast' is the definition.
'man eater' can be an answer for 'beast' (thesaurus). I am not certain of the 'fierce' bit.
'better groomed by mother' is the wordplay.
I cannot quite see how this works, but
'better' could be 'neater' (I've seen this before) and 'neater' is located in the answer.
'mother' could be 'ma' (ma can mean mother) and 'ma' is present in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for man-eater that I've seen before include "Life-threatening wild animal" , "Animal killing and feeding on humans" , "Animal known to consume humans" , "Cannibal" , "Tiger dangerous to people" .)