Diffidence, n.
Etymology: [L. diffidentia.]
1. The state of being diffident; distrust; want of confidence; doubt of the power, ability, or disposition of others. [Archaic] That affliction grew heavy upon me, and weighed me down even to a diffidence of God's mercy. Donne.
2. Distrust of one's self or one's own powers; lack of self-reliance; modesty; modest reserve; bashfulness. It is good to speak on such questions with diffidence. Macaulay. An Englishman's habitual diffidence and awkwardness of adress. W. Irving.
Syn. -- Humility; bashfulness; distrust; suspicion; doubt; fear; timidity; apprehension; hesitation. See Humility, and Bashfulness.
Shades of meaning
Fernald has no entry of its own for diffidence; he lists it under modesty.
Where he writes about it:
Diffidence is self-distrust; modesty, a humble estimate of oneself in comparison with others, or with the demands of some undertaking. — from modesty