Little time for memorandum (6)
I believe the answer is:
minute
I believe this clue is a triple definition!
'little' is the first definition.
(similar in meaning)
'time' is the second definition.
(unit of time)
'for' acts as a link.
'memorandum' is the third definition.
(I have seen 'official memorandum' mean 'minute' so perhaps 'memorandum' could also mean 'minute')
(Other definitions for minute that I've seen before include "Barely perceptible" , "official memorandum" , "Brief note" , "Small amount of time" , "Small, tiny" .)