Reveal cut in exposed rock (7)
I believe the answer is:
outcrop
'exposed rock' is the definition.
(I've seen this before)
'reveal cut' is the wordplay.
'reveal' becomes 'out' (outing is a kind of revealing).
'cut' becomes 'crop' (cropping is a kind of cutting**).
'out'+'crop'='OUTCROP'
'in' acts as a link.
(Other definitions for outcrop that I've seen before include "Visible rock formation" , "Rocky feature" , "Surface eruption of rock" , "Protruding or projecting rock" , "Cop tour around projecting layer of rock" .)