A very small bit of time (6)
I believe the answer is:
minute
I believe this is a triple definition!
'a very small' is the first definition.
(minute can mean tiny)
'bit' is the second definition.
(synonyms)
'of' acts as a link.
'time' is the third definition.
(sixty seconds)
(Other definitions for minute that I've seen before include "official memorandum" , "It's not very long" , "60 seconds; tiny" , "Brief note" , "Very short or tiny" .)