Animal fat all in on spread (7)
I believe the answer is:
lanolin
'animal fat' is the definition.
'lanolin' can be an answer for 'fat' (I've seen this before). I'm not sure about the 'animal' bit.
'all in on spread' is the wordplay.
'spread' indicates anagramming the letters.
'all'+'in'+'on'='allinon'
'allinon' with letters rearranged gives 'LANOLIN'.
Can you help me to learn more?
(Other definitions for lanolin that I've seen before include "Ointment containing wool fat" , "Oily substance on wool" , "Yellow viscous oil from animals -- in on all (anag)" , "substance found in ointments" , "Substance found on sheep's wool" .)