Farm animal, male, put in place for scientific research (4)
I believe the answer is:
lamb
'farm animal' is the definition.
(I've seen this before)
'male put in place for scientific research' is the wordplay.
'male' becomes 'm' (common abbreviation).
'put in' indicates putting letters inside.
'place for scientific research' becomes 'lab' (laboratory).
'm' going within 'lab' is 'LAMB'.
(Other definitions for lamb that I've seen before include "Young farm animal" , "English essayist" , "Mary, and Charles?" , "Youngster" , "Noted essayist - symbol of innocence" .)