noun

possession or expression of an unfavourable opinion.

Jill replied with a hint of disapproval in her voice

disapprobation,dislike,dissatisfaction,disfavour,displeasure,distaste,odium,objection,demurral,exception,dissent,disagreement,criticism,censure,condemnation,denunciation,opprobrium,blame,reproach,rebuke,reproof,remonstration,disparagement,deprecation,the thumbs down,animadversion