Not alarmed by deranged nut tossing boulder (10)
I believe the answer is:
untroubled
'not alarmed' is the definition.
The answer and definition are different parts of speech. However, adjectives and past participle verbs can occasionally define each other.
'deranged nut tossing boulder' is the wordplay.
'deranged' is an anagram indicator.
'tossing' is an anagram indicator.
'nut' with letters rearranged gives 'unt'.
'boulder' anagrammed gives 'roubled'.
'unt'+'roubled'='UNTROUBLED'
'by' acts as a link.
Can you help me to learn more?
(Other definitions for untroubled that I've seen before include "Calm, tranquil" , "Not anxious" , "Composed" .)