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' means one lot of letters go next to another.
'wicked' becomes 'vile' ('vile' can be similar in meaning to 'wicked').
're'+'vile'='REVILE'
(Other definitions for revile that I've seen before include "Abuse verbally" , "Upbraid, berate" , "Criticise - abuse" , "Abusively criticise" , "Run down" .)