Loss of red mitten, unfortunately (9)
I believe the answer is:
detriment
'loss' is the definition.
(I've seen this before)
'red mitten unfortunately' is the wordplay.
'unfortunately' indicates anagramming the letters (a bad or unfortunate spelling).
'red'+'mitten'='redmitten'
'redmitten' with letters rearranged gives 'DETRIMENT'.
'of' acts as a link.
(Other definitions for detriment that I've seen before include "State of being harmed or damaged" , "hurt" , "Damage, loss" , "Harm, damage" , "Possible loss" .)