Thing to change before morning (7)
I believe the answer is:
tonight
'before morning' is the definition.
The answer and definition can be both related to time as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'thing to change' is the wordplay.
'change' indicates anagramming the letters.
'thing'+'to'='thingto'
'thingto' is an anagram of 'TONIGHT'.
Can you help me to learn more?
(Other definitions for tonight that I've seen before include "Hotting (anag.)" , "Later today" , "late in the day" , "Later this evening" , "after supper?" .)