Crossword Genius

One decides a set time, namely before holiday (3-5)

Ross

I believe the answer is:

tie-break

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'one decides a set' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.

'time namely before holiday' is the wordplay.
'time' becomes 't' (abbreviation).
'namely' becomes 'ie' (short for 'id est', 'that is' in Latin).
'before' says to put letters next to each other.
'holiday' becomes 'break' (break can mean a holiday or time off).
't'+'ie'+'break'='TIE-BREAK'

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