Togetherness makes a tiny change for an upstart (5)
I believe the answer is:
unity
'togetherness' is the definition.
(I've seen this in another clue)
'a tiny change for an upstart' is the wordplay.
'change' indicates an anagram.
'for' is a charade indicator (letters next to each other) (I've seen this in other clues).
'an upstart' becomes 'u' (start of the word 'up').
'tiny' anagrammed gives 'nity'.
'nity' after 'u' is 'UNITY'.
'makes' acts as a link.
(Other definitions for unity that I've seen before include "Accord" , "Mitford girl" , "One of the Mitfords" , "State of togetherness" , "A single whole" .)