Criticism of a little snow, mostly (4)
I believe the answer is:
flak
'criticism' is the definition.
(I know that flak is a type of criticism)
'a little snow mostly' is the wordplay.
'a little snow' becomes 'flake' (I've seen this before).
'mostly' means to remove the last letter (most but not all of the word).
'flake' with its final letter taken away is 'FLAK'.
'of' acts as a link.
(Other definitions for flak that I've seen before include "Severe criticism" , "stick" , "Shooting" , "Bad press" , "Ground-to-air attack: verbal abuse" .)