Trump will accept no tiebreaker (3-3)
I believe the answer is:
run-off
'tiebreaker' is the definition.
I don't know anything about this answer so I can't judge whether this works.
'trump will accept no' is the wordplay.
'trump' becomes 'ruff' (synonyms).
'will accept' means one lot of letters goes inside another.
'ruff' placed around 'no' is 'RUN-OFF'.
Can you help me to learn more?
(Other definitions for run-off that I've seen before include "Draining of rainfall from an area" , "Further contest to decide a tie" .)