Engineers take wicked attack (6)
I believe the answer is:
revile
'attack' is the definition.
(thesaurus)
'engineers take wicked' is the wordplay.
'engineers' becomes 're' (Royal Engineers).
'take' is a charade indicator (letters next to each other).
'wicked' becomes 'vile' (similar in meaning).
're'+'vile'='REVILE'
(Other definitions for revile that I've seen before include "Abuse verbally" , "Upbraid, berate" , "Criticise - abuse" , "Abusively criticise" , "Run down" .)