Hero tries to break ideas man (9)
I believe the answer is:
theoriser
'ideas man' is the definition.
The definition suggests a singular noun which matches the answer.
'hero tries to break' is the wordplay.
'to break' indicates an anagram.
'hero'+'tries'='herotries'
'herotries' is an anagram of 'THEORISER'.
Can you help me to learn more?
(Other definitions for theoriser that I've seen before include "speculator" , "he thinks" , "One who reasons" , "One who has convictions" , "one who speculates" .)