Feeling or showing haughty disdain. See Synonyms at arrogant.
[Latin superciliōsus, from supercilium, eyebrow, pride : super-, super- + cilium, lower eyelid; see kel-1 in the Appendix of Indo-European roots.]
Word History: The English word supercilious ultimately derives from the Latin word supercilium, "eyebrow." Supercilium came to mean "the eyebrow as used in frowning and expressing sternness, gravity, or haughtiness." From there it developed the senses "stern looks, severity, haughty demeanor, pride." The derived Latin adjective superciliōsus meant "full of stern or disapproving looks, censorious, haughty, disdainful," as it has since it entered English as supercilious in the 1500s. The super- in the Latin word supercilium means "above," and cilium was the Latin word for "eyelid." In many of the Romance languages, this word developed into the word for "eyelash." This development is probably reflected in the scientific use in English of the word cilium, whose plural is cilia. Cilia are the minute hairlike appendages of cells or unicellular organisms that move in unison in order to bring about the movement of the cell or of the surrounding medium.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.