dead ‧ en /ˈdedn/ BrE AmE verb [transitive]
[ Word Family: noun : ↑ dead , ↑ death , deadliness; adjective : ↑ dead , ↑ deadly , ↑ deathly ; adverb : ↑ deadly , ↑ deathly ; verb : ↑ deaden ]
to make a feeling or sound less strong:
medicine to deaden the pain