Tiny moment (6)
I believe the answer is:
minute
I believe this clue is a double definition.
'tiny' is the first definition.
(minute can mean small)
'moment' is the second definition.
(both can mean a short amount of time)
(Other definitions for minute that I've seen before include "Very short or tiny" , "Immeasurably small" , "Formal note" , "A few ticks" , "official memorandum" .)