Good publican offers spirit (5)
I believe the answer is:
ghost
'spirit' is the definition.
(ghost is a kind of spirit)
'good publican' is the wordplay.
'good' becomes 'g' (abbreviation).
'publican' becomes 'host' (I've seen this in other clues).
'g'+'host'='GHOST'
'offers' acts as a link.
(Other definitions for ghost that I've seen before include "A spirit from the beyond" , "Visible manifestation of a dead person" , "suggestion" , "insubstantial presence" , "Lay down life for another in this" .)