Modern health resort according to publication (9)
I believe the answer is:
newspaper
'publication' is the definition.
(I've seen this before)
'modern health resort according' is the wordplay.
'modern' becomes 'new' ('new' is associated in meaning with 'modern').
'health resort' becomes 'spa' (I've seen this before).
'according' becomes 'per' (I've seen this in other clues).
'new'+'spa'+'per'='NEWSPAPER'
'to' is the link.
(Other definitions for newspaper that I've seen before include "Broadsheet, e.g." , "It's (mainly) black and white, and read all over!" , "Eg, The Times" , "part of the media" , "printed edition" .)