v. 使变钝( dull的第三人称单数 ); 使（兴趣、痛苦等）减少; 使麻木; 使晦暗

v make dull in appearance

v become dull or lusterless in appearance; lose shine or brightness

v deaden (a sound or noise), especially by wrapping

v make numb or insensitive

v make dull or blunt

v become less interesting or attractive

v make less lively or vigorous