Inferior to a thane, possibly (5)
I believe the answer is:
neath
'inferior' is the definition.
I know nothing about this answer so I cannot tell whether this works.
'thane possibly' is the wordplay.
'possibly' is an anagram indicator.
'thane' with letters rearranged gives 'NEATH'.
'to a' acts as a link.
Can you help me to learn more?
(Other definitions for neath that I've seen before include "Town near Swansea" , "Lower than - a town in West Glamorgan" , "not on top" , "Welsh rugby club" , "Town NE of Swansea" .)