Open, fierce contempt laced with mockery and indignation.
Open, fierce contempt laced with mockery and indignation — the most outwardly voiced of the “looking down” words.
The most active, vocal, and hot of the trio: undisguised dislike and disrespect shot through with mockery and indignation — a quick, indignant kind of contempt. Where contempt can be a silent inner state and disdain a cold withdrawal, scorn is outward-directed and demonstrative — it ridicules, scoffs, derides (“pour scorn on,” “laughed to scorn”). The clearest blend of contempt/disgust with anger. More confrontational and accusatory than its neighbors; somewhat literary in register.
Late 12c., a shortening of Old French escarn “mockery, derision,” a word of Germanic origin (cf. Old High German skern “mockery, jest”). The “break off someone's horns” story is explicitly rejected by the OED.
Stable from the start: the “mockery + contempt” cluster is present from the late 12c., and “laugh to scorn” is medieval. The agent noun scorner was once especially “a scoffer at religion,” a nuance now faded — the one notable historical shift. No reliable recent-generation shift.