The Collaborative International Dictionary of English v.0.48:
Doubt \Doubt\ (dout), v. i. [imp. & p. p. Doubted; p. pr. &
vb. n. Doubting.] [OE. duten, douten, OF. duter, doter,
douter, F. douter, fr. L. dubitare; akin to dubius doubtful.
1. To waver in opinion or judgment; to be in uncertainty as
to belief respecting anything; to hesitate in belief; to
be undecided as to the truth of the negative or the
affirmative proposition; to b e undetermined.
Even in matters divine, concerning some things, we
may lawfully doubt, and suspend our judgment.
To try your love and make you doubt of mine.
2. To suspect; to fear; to be apprehensive. [Obs.]
Syn: To waver; vacillate; fluctuate; hesitate; demur;