Embellish, v. t. [imp. & p. p. Embellished; p. pr. & vb. n. Embellishing.]
Etymology: [OE. embelisen, embelisshen, F. embellir; pref. em- (L. in) + bel, beau, beautiful. See Beauty.]
To make beautiful or elegant by ornaments; to decorate; to adorn; as, to embellish a book with pictures, a garden with shrubs and flowers, a narrative with striking anecdotes, or style with metaphors.
Syn. -- To adorn; beautify; deck; bedeck; decorate; garnish; enrich; ornament; illustrate. See Adorn.
Shades of meaning
Fernald has no entry of its own for embellish; he lists it under adorn.
Where he writes about it:
To embellish is to brighten and enliven by adding something that is not necessarily or very closely connected with that to which it is added; to illustrate is to add something so far like in kind as to cast a side-light upon the principal matter. — from adorn