Dissimilitude, n.
Etymology: [L. dissimilitudo, fr. dissimilis: cf. F. dissimilitude.]
1. Want of resemblance; unlikeness; dissimilarity. Dissimilitude between the Divinity and images. Stillingfleet.
2. (Rhet.)
A comparison by contrast; a dissimile.
Shades of meaning
Fernald has no entry of its own for dissimilitude; he lists it under difference.
He lists it without comment; the entries above explain its neighbors.