Distance marker moles tip up (8)
I believe the answer is:
milepost
'distance marker' is the definition.
(I've seen this before)
'moles tip up' is the wordplay.
'up' indicates anagramming the letters.
'moles'+'tip'='molestip'
'molestip' anagrammed gives 'MILEPOST'.
(Other definitions for milepost that I've seen before include "Distance marker" , "measure of progress" , "Eight-furlong marker" .)