Very black expression of grief (3)
I believe the answer is:
sob
'expression of grief' is the definition.
'sob' can be an answer for 'expression' (I have seen 'Expression of distress' mean 'sob' so perhaps 'expression' could also mean 'sob'). I am not certain of the 'of grief' bit.
'very black' is the wordplay.
'very' becomes 'so' (both can mean 'extremely').
'black' becomes 'b' (as in pencil classifications).
'so'+'b'='SOB'
Can you help me to learn more?
(Other definitions for sob that I've seen before include "Cry bitterly" , "Contemptible person in North America briefly" , "Weep noisily" , "making one gasp" , "Cry loudly" .)