deaden - verb

• make vague or obscure or make (an image) less visible
• cut a girdle around so as to kill by interrupting the circulation of water and nutrients
• make vapid or deprive of spirit
• lessen the momentum or velocity of
• become lifeless, less lively, intense, or active; lose life, force, or vigor
• make less lively, intense, or vigorous; impair in vigor, force, activity, or sensation
• convert (metallic mercury) into a grey powder consisting of minute globules, as by shaking with chalk or fatty oil

deaden - thesaurus

blunt   damp   dampen   girdle