Robbery makes errand boy sick inside (7)
I believe the answer is:
pillage
'robbery' is the definition.
(thesaurus)
'errand boy sick inside' is the wordplay.
'errand boy' becomes 'page' (page is a kind of errand boy).
'sick' becomes 'ill' (synonyms).
'inside' is an insertion indicator.
'page' placed around 'ill' is 'PILLAGE'.
'makes' is the link.
(Other definitions for pillage that I've seen before include "Plunder, sack" , "Sacking" , "Rob with violence" , "Violent stealing" , "Loot" .)