The servant I dismissed is furious (3)
I believe the answer is:
mad
'furious' is the definition.
(I've seen this in another clue)
'the servant i dismissed is' is the wordplay.
'the servant' becomes 'maid' (maid is a type of servant).
'dismissed' is a deletion indicator.
'is' becomes 'II' (more than one I).
'maid'+'i'='maidi'
'maidi' with 'ii' removed is 'MAD'.
(Other definitions for mad that I've seen before include "Angry or insane" , "Berserk" , "lunatic" , "Frenzied" , "Frantic" .)