1. Having or showing arrogant superiority to and disdain of those one views as unworthy; “some economists are disdainful of their colleagues in other social disciplines”; “haughty aristocrats”; “his lordly manners were offensive”; “walked with a prideful swagger”; “very sniffy about breaches of etiquette”; “his mother eyed my clothes with a supercilious air”; “shaggy supercilious camels”; “a more swaggering mood than usual”- W.L.Shirer.
2. Expressive of contempt; “curled his lip in a supercilious smile”; “spoke in a sneering jeering manner”; “makes many a sharp comparison but never a mean or snide one”.
Date “supercilious” was first used in popular English literature: sometime before 1509.
Etymology: Supercilious \Su`per*cil”i*ous\, adjective. [Latin expression superciliosus, from supercilium an eyebrow, pride; super over, cilium an eyelid; probably akin to celare to conceal. Compare to Conceal.].