Hairy dog exercising with a nurse (9)
I believe the answer is:
dangerous
'hairy' is the definition.
(thesaurus)
'dog exercising with a nurse' is the wordplay.
'exercising with' indicates an anagram.
'a'+'nurse'='anurse'
'dog' with its letters anagrammed with 'anurse' can make 'DANGEROUS'.
(Other definitions for dangerous that I've seen before include "Hazardous" , "Not safe" , "High-risk" , "Posing a hazard" , "Perilous, unsafe" .)