Better water frozen in northern river (5)
I believe the answer is:
nicer
'better water' is the definition.
'nicer' can be an answer for 'better' (I've seen this before). I am not certain of the 'water' bit.
'frozen in northern river' is the wordplay.
'frozen' becomes 'ice' (I've seen this in other clues).
'in' indicates putting letters inside.
'northern' becomes 'n' (abbreviation e.g. N. Ireland).
'river' becomes 'r' (abbreviation for river).
'n'+'r'='nr'
'ice' inserted within 'nr' is 'NICER'.
Can you help me to learn more?
(Other definitions for nicer that I've seen before include "better" , "more likeable" , "it's more appealing" , "improved" , "comparatively agreeable" .)