No restricting one in series from an older time (6)
I believe the answer is:
senior
'from an older time' is the definition.
(senior means older)
'no restricting one in series' is the wordplay.
'restricting' indicates putting letters inside.
'one' becomes 'I' (Roman numeral).
'in' indicates putting letters inside.
'series' becomes 'ser' (abbreviation for series).
'no' going around 'i' is 'nio'.
'nio' placed inside 'ser' is 'SENIOR'.
(Other definitions for senior that I've seen before include "Higher in rank or age" , "Elder (of two)" , "High-ranking" , "Superior - elder" , "High in rank" .)