The antonyms for the phrase "gives boost to" are "reduces," "decreases," "hampers," "hinders," and "weaken." These words imply a negative or opposite effect on the specific action of boosting. For instance, reducing would mean to decrease in value or effectiveness. Hampering and hindering indicate obstructions or obstacles that prevent progress. Weakening implies a reduction in strength or vigor. It is important to use the appropriate antonym when the context requires it, as it is a way of conveying a different message and highlighting a different perspective.