I count as mad (5)
I believe the answer is:
irate
'mad' is the definition.
(thesaurus)
'i count' is the wordplay.
'count' becomes 'rate' (I've seen this in other clues).
'i'+'rate'='IRATE'
'as' acts as a link.
(Other definitions for irate that I've seen before include "ranting" , "A tier (anag)" , "Extremely angry" , "Fuming" , "will be up in arms" .)