untarnished
/ˌʌnˈtɑːnɪʃt/adjective
1- (of metal or metalware) not having lost its lustre, especially as a result of exposure to air or moisture（金属, 金属物品）未失去光泽的, 未变色的。
1.1
- figurative 〈喻〉not made less valuable or respected未失去价值的; 未受玷污的：
his ministers enjoyed an untarnished reputation.
他的大臣们享有清白的名声。