Roland changed his name (6)
I believe the answer is:
arnold
'his name' is the definition.
The definition suggests a singular noun which matches the answer.
'roland changed' is the wordplay.
'changed' indicates an anagram.
'roland' with letters rearranged gives 'ARNOLD'.
Can you help me to learn more?
(Other definitions for arnold that I've seen before include "Headmaster, poet or composer" , "-- Wesker, playwright" , "Sir Malcolm -, composer (Bridge over the River Kwai)" , "Matthew --, English poet" , "Overcome (obstacle)" .)