Start to include sailor in attack (3,5)
I believe the answer is:
set about
'attack' is the definition.
(thesaurus)
'start to include sailor' is the wordplay.
'start' becomes 'setout' ('set out' can be a synonym of 'start'**).
'to include' indicates putting letters inside.
'sailor' becomes 'ab' (abbreviation for able seaman).
'setout' placed around 'ab' is 'SET ABOUT'.
'in' is the link.
(Other definitions for set about that I've seen before include "Get cracking" , "Start to do something with determination" , "Begin - attack" , "Embark upon" .)