Embolden, v. t. [imp. & p. p. Emboldened; p. pr. & vb. n. Emboldening.]
To give boldness or courage to; to encourage. Shak. The self-conceit which emboldened him to undertake this dangerous office. Sir W. Scott.
Shades of meaning
Fernald has no entry of its own for embolden; he lists it under abet.
He lists it without comment; the entries above explain its neighbors.