Pretty nieces short of energy, unusually cold (6)
I believe the answer is:
scenic
'pretty' is the definition.
(thesaurus)
'nieces short of energy unusually cold' is the wordplay.
'short of' is a deletion indicator.
'energy' becomes 'e' (physics symbol as in E=mc2).
'unusually' indicates anagramming the letters.
'cold' becomes 'c' (eg on taps).
'nieces' with 'e' removed is 'nices'.
'nices' is an anagram of 'sceni'.
'sceni'+'c'='SCENIC'
(Other definitions for scenic that I've seen before include "Dramatic, theatrical" , "Providing beautiful views" , "Having colourful views, like some routes" , "Relating to beautiful view" , "Like beautiful location" .)