a. [ L. superciliosus, fr. supercilium an eyebrow, pride; super over, + cilium an eyelid; probably akin to celare to conceal. Cf. Conceal. ] Lofty with pride; haughty; dictatorial; overbearing; arrogant; as, a supercilious officer; asupercilious air; supercilious behavior. -- Su`per*cil"i*ous*ly, adv. -- Su`per*cil"i*ous*ness, n. [ 1913 Webster ]