Definition
To not trust or believe someone or what they say.
不相信（某人）；懷疑（某人的話）
She always tells the truth, so I see no reason to doubt her.
她總是說實話，所以我看不出有任何理由懷疑她。
Despite his past mistakes, I now choose to believe him and no longer doubt his word.
儘管他過去犯過錯誤，我現在選擇相信他，不再懷疑他的話。
When I heard those rumors, I started to doubt his loyalty a bit.
當我聽到那些謠言時，我開始有點懷疑他的忠誠。