Resolution: enact it in some form before start of year (8)
I believe the answer is:
tenacity
'start of year' is the definition.
The answer and definition can be both human attributes as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'resolution enact it in some form before' is the wordplay.
'resolution' indicates an anagram.
'it' becomes 't' (abbreviation. e.g. in 'tis).
'some' suggests taking the first letters.
'form before' becomes 'y' (I am not sure about this - if you are sure you should believe this answer much more).
The initial letter of 'in' is 'i'.
'enact'+'t'+'i'='enactti'
'enactti' anagrammed gives 'tenacit'.
'tenacit'+'y'='TENACITY'
Can you help me to learn more?
(Other definitions for tenacity that I've seen before include "Dogged resolve" , "Stubbornness, determination" , "Perseverance, doggedness" , "Bulldog quality" , "Staying power" .)