Found 20 stronger alternatives to upgrade your writing.
Bad manners
Nuance: Impolite
Behavioral.
Boring
He was mean to the waiter.
Better
He was rude to the waiter.
General negative
Nuance: Naughty
Childish.
Boring
Don't be mean.
Better
Don't be bad.
Not caring
Nuance: Not nice
Gentle criticism.
Boring
It was mean to say that.
Better
It was unkind to say that.
Causing pain
Nuance: Painful
Focus on effect.
Boring
Mean words.
Better
Hurtful words.
Wanting to cause pain
Nuance: Sadistic
Enjoying the pain.
Boring
Mean punishment.
Better
Cruel punishment.
Unpleasant / dirty
Nuance: Gross/Mean
Disgusting/mean.
Boring
A mean comment.
Better
A nasty comment.
Severe / rough
Nuance: Severe
Too strong.
Boring
Mean criticism.
Better
Harsh criticism.
No emotion
Nuance: Unfeeling
Lack of warmth.
Boring
A mean stare.
Better
A cold stare.
Petty revenge
Nuance: Vengeful
Done to hurt.
Boring
Mean gossip.
Better
Spiteful gossip.
Enemy-like
Nuance: Aggressive
War-like.
Boring
Mean behavior.
Better
Hostile behavior.
Caring only for self
Nuance: Self-centered
Motivation.
Boring
Mean actions.
Better
Selfish actions.
Attacking
Nuance: Attacking
Action.
Boring
Mean shouting.
Better
Aggressive shouting.
Evil intent
Nuance: Evil intent
Planned evil.
Boring
Mean lies.
Better
Malicious lies.
Seeking revenge
Nuance: Revenge-seeking
Obsessed with revenge.
Boring
A mean ex-friend.
Better
A vindictive ex-friend.
Wishing evil on others
Nuance: Evil
Supernatural/deep evil.
Boring
A mean spirit.
Better
A malevolent spirit.
Unfeeling
Nuance: Heartless
No empathy.
Boring
Mean disregard.
Better
Callous disregard.
Enjoying pain
Nuance: Sick
Sick pleasure.
Boring
A mean grin.
Better
A sadistic grin.
Violent / savage
Nuance: Violent
Animalistic.
Boring
A mean attack.
Better
A vicious attack.
No heart
Nuance: Empty
Emotional emptiness.
Boring
A mean decision.
Better
A heartless decision.
Acting superior
Nuance: Superior
Thinking you are better.
Boring
Mean tone.
Better
Condescending tone.