Labour to secure source of meat - such as this? (4)
I believe the answer is:
lamb
'as this?' is the definition.
The definition suggests a singular noun which matches the answer.
'labour to secure source of meat' is the wordplay.
'labour' becomes 'lab' (abbreviation).
'to secure' indicates putting letters inside (inserted letters are secured inside).
'source of' indicates taking the first letters.
The initial letter of 'meat' is 'm'.
'lab' placed around 'm' is 'LAMB'.
'such' acts as a link.
(Other definitions for lamb that I've seen before include "Young sheep" , "Noted essayist - symbol of innocence" , "Young shee" , "Charles ---, essayist; meek animal" , "Mary, and Charles?" .)