Terrible funeral song not good (4)
I believe the answer is:
dire
'terrible' is the definition.
(synonyms)
'funeral song not good' is the wordplay.
'funeral song' becomes 'dirge' (I've seen this before).
'not' indicates named letters should be taken away.
'good' becomes 'g' (abbreviation).
'dirge' with 'g' taken away is 'DIRE'.
(Other definitions for dire that I've seen before include "Very serious indeed" , "Really dreadful - ride on" , "Of very poor quality" , "Terrible display" , "Terrible; urgent" .)