Originally posted by Ghost of a Duke... anger is 'a strong feeling that makes you want to hurt someone or be unpleasant because of something unfair or unkind that has happened.' Cambridge dictionary).
That is not a good definition, imo. Angry people don't necessarily desire to be unpleasant.
a strong feeling of displeasure and usually of antagonism
merriam/webster
a feeling of tension and hostility, usually caused by anxiety aroused by a perceived threat to one's self, possessions, rights, or values.
A strong emotion aroused by a sense of wrong, whether justified or not.
the FreeDictionary
And so on. Anger is a feeling that you need to defend yourself, now. Controlling your anger is a good thing, but being unable to feel it ever at all is a weakness - a malfunction. It should have a name.
Suggestion for a name for the pathological inability to feel the basic emotion of anger, culled from StackExchange:
serenity
Imperturbable
Apathy
Defeatism
Resignation
Passivity
Complacency
alexithymia
non-irascible
aorgesia
numb
Emotional detachment (inability to connect)
emotional numbing
unirascible
Wrathless
Unincensed
Unspleened
spleenless
Angerless
avirulent
stomachless
gall-less