Market style that’s seen at Troon? (7)
I believe the answer is:
fairway
'that's seen at troon?' is the definition.
(part of a golf course - Troon is a golf course)
'market style' is the wordplay.
'market' becomes 'fair' (I've seen this before).
'style' becomes 'way' (synonyms).
'fair'+'way'='FAIRWAY'
(Other definitions for fairway that I've seen before include "Part of golf course between tee and green" , "Golf course area between tee and green" .)