deadening
dead-en-ing
adjective
Causing something to become less intense, lively, or sensitive; dulling.
"The deadening routine made him feel numb."
noun
The act or process of making something less intense, lively, or sensitive.
"The deadening of sound was quite effective."
Thesaurus
Synonyms: stultification, constipation, impairment, irksome, ho-hum, uninteresting, dull, boring, slow, tedious, wearisome, tiresome