A vile beach resort within reach (10)
I believe the answer is:
achievable
'within reach' is the definition.
(I've seen this in another clue)
'a vile beach resort' is the wordplay.
'resort' is an anagram indicator.
'vile'+'beach'='vilebeach'
'vilebeach' is an anagram of 'chievable'.
'a'+'chievable'='ACHIEVABLE'
(Other definitions for achievable that I've seen before include "can be reached" , "Able to be accomplished" , "Doable, winnable" .)