Leading surrealists exhibited in the gallery show preference (5)
I believe the answer is:
taste
'preference' is the definition.
(I know this)
'leading surrealists exhibited in the gallery' is the wordplay.
'leading' indicates taking the first letters.
'exhibited in' means one lot of letters goes inside another.
'the gallery' becomes 'tate' (Tate Modern, Tate Britain etc).
The first letter of 'surrealists' is 's'.
's' put into 'tate' is 'TASTE'.
'show' is the link.
(Other definitions for taste that I've seen before include "Experience - discrimination" , "Sample - discrimination" , "Nice distinction felt in the mouth" , "To eat sparingly" , "Preference" .)