Fat reduced by female dog (3)
I believe the answer is:
lab
'female dog' is the definition.
'lab' can be an answer for 'dog' (short for labrador). I'm not sure about the 'female' bit.
'fat reduced' is the wordplay.
'fat' becomes 'flab' (flab is a kind of fat).
'reduced' means to remove the first letter.
'flab' with its first letter removed is 'LAB'.
'by' acts as a link.
Can you help me to learn more?
(Other definitions for lab that I've seen before include "Science room" , "Room for scientist" , "Scientist's workroom" , "retriever" , "Experimental facility" .)