Calm animal, good in a hot country (7)
I believe the answer is:
assuage
'calm' is the definition.
(I know that assuage is a kind of calm)
'animal good in a hot country' is the wordplay.
'animal' becomes 'ass' (term for a donkey).
'good' becomes 'g' (abbreviation).
'in' indicates putting letters inside.
'a hot country' becomes 'uae' (I can't justify this - if you can you should believe this answer much more).
'g' placed within 'uae' is 'uage'.
'ass'+'uage'='ASSUAGE'
Can you help me to learn more?
(Other definitions for assuage that I've seen before include "Make less intense; satisfy" , "Make less severe, pain or guilt, say" , "Allay, alleviate" , "Make less severe, pain or hunger, say" , "Provide physical or mental relief -- satisfy" .)