To discredit someone or something means to cause them to lose people's respect or trust.
例句
...a secret unit within the company that had been set up to discredit its major rival...公司里設立的敗壞其主要競爭對手名聲的秘密部門He says his accusers are trying to discredit government foreign-aid policies...他說他的責難者試圖使政府的對外援助政策名聲掃地。
VERB
使不可信;證實…是假的
To discredit an idea or evidence means to make it appear false or not certain.
例句
They realized there would be difficulties in discrediting the evidence.他們意識到要揭穿這個證據困難重重。
英英詞典釋義
Adjective
1. being unjustly brought into disrepute;
"a discredited politician""her damaged reputation"