Citrus tree almost devoured by cold weather (7)
I believe the answer is:
Here is my best explanation:
'weather' is the definition.
'citrus tree almost devoured by cold' is the wordplay.
'citrus tree' becomes 'lime' (lime is a kind of citrus tree).
'almost' means to remove the last letter (most of the word but not all of it).
'devoured' becomes 'ate' (I've seen this before).
'by' means one lot of letters go next to another.
'cold' becomes 'c' (eg on taps).
'lime' with its last letter taken away is 'lim'.
'limate' after 'c' is 'CLIMATE'.
(Other definitions for climate that I've seen before include "Mail, etc (anag.)", "Prevailing state", "Atmosphere", "Mood", "National weather conditions", "Weather conditions of a region", "Cite Mal (anag.)", "Long-term prevalent weather conditions", "Weather etc" and "Prevailing weather conditions".)