- doubt, uncertainty, incertitude, dubiety, doubtfulness, dubiousness - the state of being unsure of something
--1 is a kind of cognitive state, state of mind
--1 has particulars:mental reservation, reservation, arriere pensee; misgiving, mistrust, distrust, suspicion; incredulity, disbelief, skepticism, mental rejection; indecision, indecisiveness, irresolution; suspense - doubt, dubiousness, doubtfulness, question - uncertainty about the truth or factuality of existence of something; "the dubiousness of his claim"; "there is no question about the validity of the enterprise"
--2 is a kind of uncertainty, uncertainness