Very cold part of anticyclone (3)
I believe the answer is:
icy
'very cold' is the definition.
(I've seen this before)
'part of anticyclone' is the wordplay.
'part of' indicates a hidden word.
'ICY' is hidden in the letters of 'anticyclone'.
(Other definitions for icy that I've seen before include "Freezing cold" , "Distant - freezing" , "Frosty and slippy" , "frozen over!" , "Very cold, unfriendly" .)