intransitive verb

1. to be uncertain in opinion or belief; be undecided
2. to be inclined to disbelief
3. Archaic to hesitate

Etymology: ME douten < OFr douter < L dubitare, to waver in opinion < dubius, dubious; -b- reintroduced, after L, in 16th c.

transitive verb

1. to be uncertain about; question; feel distrust of
2. to be inclined to disbelieve; be skeptical of
3. Archaic to be fearful or suspicious of

noun

1. 1. a wavering of opinion or belief; lack of conviction; uncertainty
   2. lack of trust or confidence
2. a condition of uncertainty the outcome was in doubt
3. an unsettled point or matter; difficulty
4. Obsolete apprehension or fear