0 present participle of doubt
1 to not feel certain or confident about something or to think that something is not probable:
I doubt whether it'll work.
He gave his word that he would marry her and she had no cause to doubt him.
He'd been behaving so strangely that they began to doubt his sanity.
I only caught a fleeting glimpse of the driver of the getaway car, but I doubt I would recognize her if I saw her again.
No one doubted that the president was a man of the highest integrity.
In the end, we will raise grounds for doubting that "causal" is an unambiguously perspicacious word here.
There is no doubting the eminent seriousness of the author and the admirable competence he brings to bear on his ambitious task.
There is plenty of reason for doubting his thesis in the historical record of the 1930s.
