Nouns

(n)contrast, direct contrastthe opposition or dissimilarity of things that are compared“in contrast to”, “by contrast”
(n)contrastthe act of distinguishing by comparing differences
(n)line, dividing line, demarcation, contrasta conceptual separation or distinction“there is a narrow line between sanity and insanity”
(n)contrastthe perceptual effect of the juxtaposition of very different colors
(n)contrastthe range of optical density and tone on a photographic negative or print (or the extent to which adjacent areas on a television screen differ in brightness)

Verbs

(v)contrastput in opposition to show or emphasize differences“The middle school teacher contrasted her best student's work with that of her weakest student”
(v)contrast, counterpointto show differences when compared; be different“the students contrast considerably in their artistic abilities”