Are old bats used for Test? (6)
I believe the answer is:
ordeal
'for test?' is the definition.
(thesaurus)
'are old bats' is the wordplay.
'bats' indicates anagramming the letters (slang for mad).
'are'+'old'='areold'
'areold' is an anagram of 'ORDEAL'.
'used' is the link.
(Other definitions for ordeal that I've seen before include "very hard test" , "Difficult or arduous experience" , "Difficult experience that tests endurance" , "Severe or trying experience" , "Disturbing experience" .)