Sample from federal period (3)
I believe the answer is:
era
'period' is the definition.
(I know that era is a type of period)
'sample from federal' is the wordplay.
'sample from' says the answer is hidden in the clue (a sample of letters from the clue).
'ERA' can be found hidden inside 'federal'.
(Other definitions for era that I've seen before include "Memorable period" , "Stage" , "8" , "Long period of time" , "Epoch, period" .)