Mixing two arts in the most serious case (2,5)
I believe the answer is:
at worst
'in the most serious case' is the definition.
I can't tell whether this defines the answer.
'mixing two arts' is the wordplay.
'mixing' is an anagram indicator.
'two'+'arts'='twoarts'
'twoarts' anagrammed gives 'AT WORST'.
Can you help me to learn more?
(Other definitions for at worst that I've seen before include "In the most negative circumstances" , "most pessimistically" , "Taking blackest view" , "Taking the most pessimistic view" , "in the most serious state" .)