Cashier’s right — a very boring tourist (9)
I believe the answer is:
traveller
'tourist' is the definition.
(I've seen this before)
'cashier's right a very boring' is the wordplay.
'cashier' becomes 'teller' (synonyms).
'right' becomes 'r' (common abbreviation).
'a very' becomes 'av' (I've seen this in other clues).
'boring' means one lot of letters goes inside another (some letters must 'bore' a hole into other letters).
'r'+'av'='rav'
'teller' going around 'rav' is 'TRAVELLER'.
(Other definitions for traveller that I've seen before include "Itinerant" , "asked if anybody was there" , "Representative" , "becoming less narrow-minded over time?" , "Salesman" .)