To tarnish something is to make it dirty or defective. When you tarnish a reputation, you make it difficult for someone to be trusted or respected.
He tarnished his image by cheating on his exams.
The new paint is going to tarnish the wood furniture.
verb
To oxidize or discolor due to oxidation.
verb
To soil, sully, damage or compromise
verb
To lose its lustre or attraction; to become dull.
adjective
Discolored or blemished.
adjective
(by extension, of one's reputation, name or word) Sullied or dishonored.
1
It tarnishes the neutral tone of the color.
2
It tarnishes the neutral tone of the entry.
3
Rather they tarnish it and dishonor the profession.
4
In the meantime, it won't tarnish the reputation or anything.
5
Defamation means tarnishing the reputation of someone.
6
Persistent rumours of corruption tarnished the image of the Government.
7
Deletion would tarnish the image and reputation of the project.
8
The article doesn't try to tarnish the image of India.
9
It will not fade or tarnish, and is safe from the dampness, wind and rain.
10
It is bizarre to claim that the public comments somehow tarnish the source.