Sees Carl is strangely unconcerned (8)
I believe the answer is:
careless
'unconcerned' is the definition.
(associated in meaning)
'sees carl is strangely' is the wordplay.
'is strangely' indicates an anagram.
'sees'+'carl'='seescarl'
'seescarl' is an anagram of 'CARELESS'.
(Other definitions for careless that I've seen before include "Marked by lack of attention" , "Inattentive to risk" , "Inattentive to one's work" , "Not careful or thorough enough" , "impetuous" .)