Found 30 stronger alternatives to upgrade your writing.
General / very bad
Nuance: Strong dislike
Common strong negative.
Boring
That was a bad movie.
Better
That was a terrible movie.
General / unpleasant
Nuance: Disgust
Stronger than bad.
Boring
The smell was bad.
Better
The smell was awful.
Personality / cruel
Nuance: Cruel
Specific to behavior.
Boring
Don't be bad to your sister.
Better
Don't be mean to your sister.
Behavior / kids/pets
Nuance: Mischievous
Playful/mild scolding.
Boring
The puppy was bad today.
Better
The puppy was naughty today.
Incorrect / immoral
Nuance: Incorrect
Moral/factual tone.
Boring
It is bad to steal.
Better
It is wrong to steal.
Health / feeling ill
Nuance: Ill
Specific to health.
Boring
I feel bad today.
Better
I feel sick today.
Physical pain
Nuance: Painful
Specific to injury.
Boring
My leg is bad.
Better
My leg is hurt.
Fear / frightening
Nuance: Frightening
Specific to fear.
Boring
I had a bad dream.
Better
I had a scary dream.
Food / decayed
Nuance: Decayed
Specific to food spoilage.
Boring
The apple is bad.
Better
The apple is rotten.
Quality / low standard
Nuance: Low quality
Formal/critical tone.
Boring
The service was bad.
Better
The service was poor.
Safety / dangerous
Nuance: Dangerous
Warning tone.
Boring
Smoking is bad for your health.
Better
Smoking is harmful to your health.
Attitude / opposite of positive
Nuance: Pessimistic
Formal/psychological tone.
Boring
He has a bad attitude.
Better
He has a negative attitude.
Experience / not nice
Nuance: Discomfort
Polite but clear criticism.
Boring
We had a bad experience.
Better
We had an unpleasant experience.
Weather / injury / seriousness
Nuance: Serious
Urgent/serious tone.
Boring
A bad storm is coming.
Better
A severe storm is coming.
Comparison / worse than others
Nuance: Low quality
Formal comparison.
Boring
This product is bad compared to the other.
Better
This product is inferior to the other.
Emotion / conscience
Nuance: Regretful
Specific emotion.
Boring
I feel bad about lying.
Better
I feel guilty about lying.
Opinion / reviews
Nuance: Disappointing
Business/formal tone.
Boring
The decision was bad for us.
Better
The decision was unfavorable for us.
Disgusting / mean
Nuance: Gross/Painful
Strong sensory word.
Boring
He had a bad cut on his arm.
Better
He had a nasty cut on his arm.
Very bad / fearful
Nuance: Gloomy
Old-fashioned/dramatic.
Boring
The weather was bad.
Better
The weather was dreadful.
Shockingly bad
Nuance: Overwhelming
Exaggerated/strong tone.
Boring
The traffic was bad.
Better
The traffic was horrendous.
Extremely bad quality
Nuance: Unacceptable
Teacher-frown word.
Boring
His spelling is bad.
Better
His spelling is atrocious.
Causing harm (formal)
Nuance: Damaging
High-level essay word.
Boring
Pollution is bad for the environment.
Better
Pollution is detrimental to the environment.
Ethically wrong
Nuance: Unethical
Serious moral judgment.
Boring
Lying was bad.
Better
Lying was immoral.
Dishonest / evil (systems/people)
Nuance: Dishonest
Political/legal tone.
Boring
The mayor was bad.
Better
The mayor was corrupt.
Disgusting / evil
Nuance: Disgusting
Strong emotional condemnation.
Boring
What a bad thing to say!
Better
What a vile thing to say!
Evil intentions
Nuance: Evil
Advanced literary word.
Boring
The villain had a bad plan.
Better
The villain had a malevolent plan.
Unfavorable (conditions/effects)
Nuance: Harmful
Medical/scientific.
Boring
The medication had bad side effects.
Better
The medication had adverse side effects.
Below average standard
Nuance: Disappointing
Professional criticism.
Boring
His performance was bad.
Better
His performance was subpar.
Suggesting something bad will happen
Nuance: Foreboding
Atmospheric/suspenseful; suggests trouble ahead.
Boring
A bad feeling settled over the town.
Better
An ominous feeling settled over the town.
Deserving strong blame
Nuance: Shameful
Very strong formal condemnation.
Boring
His actions were bad.
Better
His actions were reprehensible.