not willing or not able to believe something; showing a lack of ability to believe something compare credulous不肯相信的;不能相信的;表示怀疑的 Oxford Collocations DictionaryIncredulous is used with these nouns:- look
Word Origin16th cent.: from Latin incredulus (from in- ‘not’ + credulus ‘believing, trusting’, from credere ‘believe’) + -ous.