Location, we're told, upset Welshman, a tourist (9)
I believe the answer is:
sightseer
'a tourist' is the definition.
(I know that sightseer is a type of tourist)
'location we're told upset welshman' is the wordplay.
'location' becomes 'site' (site is a kind of location).
'we're told' shows a homophone (sound like).
'upset' is a reversal indicator.
'welshman' becomes 'rees' (I've seen this in other clues).
'site' is a homophone of 'sight'.
'rees' back-to-front is 'seer'.
'sight'+'seer'='SIGHTSEER'
(Other definitions for sightseer that I've seen before include "Rubberneck" , "Visitor to famous locations" , "Tourist visiting scenes of interest" , "Tripper" .)