[I believe, not only ideas but the correct usage of language plays an important role in forming any definition. Since I am not a native speaker or a linguist what I can do is to give an idea regarding the definition.]
One's all doubts end only by the unification of one's self with the Ultimate Truth (In other words, by the realization of one's real nature). Until then there must be doubt to all who haven't reached that level...at least a little. ("O Truth/God, who are you?" This is also a doubt.) Also, some people withdraw themselves and live a solitary life after their doubts completely burnt out. (I mean, after their Truth realization...) This shows they have no desires at all.
Desires and wishes keep our life going on...I didn't forget it. Keeping the aforesaid idea in mind I shall try to define 'doubt' (in terms of justification, belief and Truth) if you are badly in need of it. Since we want more precisely, I didn't try to compare the meaning given in dictionaries or in any other references including Wittgenstein's Epistemology. So I didn't use give importance to the word, 'feeling'.
Doubt is the driving force that emerges from the mind, which subsides only when one's all beliefs are burnt out by getting justification without a second thing and that happens by the realization of the Truth.
Here, I can't substitute the words desire or wish for the word, 'doubt' because the one who has desire/wish must still have doubts. But if one's doubts are completely vanished, he will have no desire/wish at all.
The following link might be useful to understand two words related to the mind:
Vikalpa literally means ‘doubt,’ ‘choice’.
The word Vikalpa has several senses. It's different inference as per
varied theories is as follows:
When manas or the mind is defined as that part of the antahkaraṇa
which is responsible for saṇkalpa and vikalpa, the word vikalpa stands