Vituperative
/vaɪˈtuːpəreɪtɪv/
Definition 1 of 1
Pro Tip 1/3Negative Tone
Vituperative language has a strong negative and critical tone, suggesting deep disrespect or disapproval. 
The vituperative feedback was so harsh it left the author in shock.
Pro Tip 2/3Harsh Critique
Use 'vituperative' to describe extremely harsh and critical comments that can be emotionally damaging. 
The vituperative review of the play discouraged the actors.
Pro Tip 3/3Intensity
'Vituperative' implies more intensity and contempt than simply calling criticism 'negative' or 'unfavorable'. 
Her vituperative speech against the proposed law rallied the opposition.