Doubt

dout: This word, found only a score of times in the Bible, translates nevertheless about half as many different Hebrew and Greek originals with a corresponding variety of meanings.

⇒See a list of verses on DOUBTING in the Bible.

In Ge 37:33 "without doubt" is to be taken in the common sense of "certainly"; in Job 12:2 in the sarcastic sense of "indeed!" In Da 5:12,16, it is used as a difficult problem or mystery to be explained, and these are the only cases of its employment in the Old Testament.

In the New Testament it is about equally used to translate diaporeo, and diakrino, and their cognates. The first means "to be without resource," "utterly at a loss," "nonplussed"; and the second, "to judge diversely." For the first, see Joh 13:22; Ac 2:12 the King James Version; Ac 5:24 the King James Version; Ac 10:17 the King James Version; Ac 25:20 the King James Version; and Ga 4:20 the King James Version. For the second see Mt 21:21; Mr 11:23; Ac 10:20; Ro 14:23. The last-named is deserving of particular attention. "He that doubteth is condemned (the King James Version "damned") if he eat," means that in a case of uncertainty as to one's Christian liberty, it were better to err on the side of restraint. In Lu 12:29 "to be of doubtful mind" (meteorizo, literally, "to suspend"; see Thayer, under the word), means "to be driven by gusts," or "to fluctuate in mid-air."

⇒See the definition of doubt in the KJV Dictionary

Here, as in Mt 14:31, "doubt" does not indicate a lack of faith, but rather "a state of qualified faith": its weakness, but not its absence.

In Joh 10:24 "doubt" translates airo psuchen, which literally means "to lift up the soul" or "to keep one in suspense"; so the Revised Version (British and American).