Point to setback after dream start (3)
I believe the answer is:
dot
'point' is the definition.
(synonyms)
'to setback after dream start' is the wordplay.
'setback' says the letters should be written in reverse.
'after' says to put letters next to each other.
'start' says to take the initial letters.
The first letter of 'dream' is 'd'.
'to' back-to-front is 'ot'.
'ot' after 'd' is 'DOT'.
(Other definitions for dot that I've seen before include "Full stop, point" , "A point, small round mark" , "Small round spot" , "One of the signals in Morse code" , "Speck; dowry" .)