Drunken purser is to stagger (8)
I believe the answer is:
surprise
'stagger' is the definition.
(thesaurus)
'drunken purser is' is the wordplay.
'drunken' indicates an anagram.
'purser'+'is'='purseris'
'purseris' is an anagram of 'SURPRISE'.
'to' acts as a link.
(Other definitions for surprise that I've seen before include "Startle, astonish" , "Unexpected or astonishing event" , "Sudden unexpected event" , "Sudden astounding event" , "Take unawares" .)