'self-doubting' originates from the combination of 'self' and 'doubt,' where 'self' refers to one's own person and 'doubt' means to be uncertain or lack confidence.

'self-doubt' evolved from the Old English word 'dūfan,' meaning 'to plunge or sink,' which later took on the metaphorical sense of sinking into uncertainty.

Initially, it meant 'to plunge into uncertainty,' but over time it evolved into its current meaning of 'lacking confidence in oneself.'