Hairy doctor argued with son (9)
I believe the answer is:
dangerous
'hairy' is the definition.
(hairy can informally mean dangerous or hazardous)
'doctor argued with son' is the wordplay.
'doctor' is an anagram indicator.
'with' says to put letters next to each other.
'argued' after 'son' is 'sonargued'.
'sonargued' with letters rearranged gives 'DANGEROUS'.
(Other definitions for dangerous that I've seen before include "High-risk" , "Hazardous" , "Harmful, injurious" , "posing a threat" , "Insecure" .)