In Anglo-Saxon England, a man who ranked between a freeman and a hereditary noble (5)

I believe the answer is:
thane
(Other definitions for thane that I've seen before include "Macbeth's Cawdor title" , "Medieval Scottish clan chief" , "Anglo-Saxon aristocrat - old Scottish clan chief" , "Old lord" , "Macbeth became - of Cawdor" .)