Ex-president of America beset by terrible anger (6)
I believe the answer is:
reagan
'ex-president' is the definition.
Both the answer and definition are singular nouns.
Perhaps they are linked in a way I don't understand?
'america beset by terrible anger' is the wordplay.
'america' becomes 'a' (common abbreviation eg in USA).
'beset by' is an insertion indicator ('beset' could historically mean 'cover').
'terrible' indicates an anagram.
'anger' is an anagram of 'reagn'.
'a' going inside 'reagn' is 'REAGAN'.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for reagan that I've seen before include "Ronald . . . . . ., a film star and president" , "Actor seen in old movies" , "Ronald ..., ex-president of USA" , "US president, 1981-89" , "US president nineteen eighty one to ninteen eighty nine" .)