Gather graduate’s captivated by Anglo-Saxon (5)
I believe the answer is:
amass
'gather' is the definition.
(amass can mean to collect or gather)
'graduate's captivated by anglo-saxon' is the wordplay.
'graduate's' becomes 'MA's' (abbreviation for Master of Arts).
'captivated by' indicates putting letters inside.
'anglo-saxon' becomes 'AS' (abbreviation for Anglo-Saxon).
'mas' put inside 'as' is 'AMASS'.
(Other definitions for amass that I've seen before include "Accumulate, heap up" , "Sodium chloride" , "Accrue, heap up" , "Collect or gather" , "Stock up on" .)