"doubtfulness, dubiousness," 1650s, from Late Latin dubietas "doubt, uncertainty," from Latin dubius "vacillating, fluctuating," figuratively "wavering in opinion, doubting" (see dubious). Earlier in the same sense were dubiosity (1640s), dubiousness (1650s); also see dubitation.
Ignorance is the mother of two filthy daughters; the first daughter of Ignorance is called dubiety, or doubtfulnesse, which is a continual wavering in opinion; a knowing man hath a fixt spirit, and settled judgement, but an ignorant man is a double-minded man, though he be never so resolute and wilful in his opinions. [W. Geering, "The Mischiefes and Danger of the Sin of Ignorance," London, 1659]
updated on October 13, 2018