Reveal chap wearing runners on a regular basis (7)
I believe the answer is:
uncover
'reveal' is the definition.
(I know that reveal can be written as uncover)
'chap wearing runners on a regular basis' is the wordplay.
'chap' becomes 'cove' (British slang term).
'wearing' is an insertion indicator.
'on a regular basis' means one should take alternating letters.
The alternating letters of 'runners' are 'unr'.
'cove' going into 'unr' is 'UNCOVER'.
(Other definitions for uncover that I've seen before include "bare" , "Strip off" , "Expose, unveil" , "show?" , "Make visible" .)