Time for grand big celebration (5)

I believe the answer is:

treat

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'celebration' is the definition.
(I've seen this before)

I don't understand the rest of the clue.

(Other definitions for treat that I've seen before include "Pay for - minister to - deal with" , "Special delight; handle" , "Deal with sickness" , "Doctor, manage" , "Deal with - source of great pleasure" .)

I've seen this clue in The Hindu.

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