cir·cum·flex (sûr?k?m-fl?ks?)n. Any of several marks, especially ( ^ ), used over a vowel in certain languages or in phonetic keys to indicate quality of pronunciation.adj.1. Having this mark.2. Curving around: a circumflex blood vessel.[From Latin circumflexus, bent around, circumflex, past participle of circumflectere, to bend around : circum-, circum- + flectere, to bend.]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.circumflex (?s??k?m?fl?ks) n (Phonetics & Phonology) a mark (^) placed over a vowel to show that it is pronounced with rising and falling pitch, as in ancient Greek, as a long vowel rather than a short one, as in French, or with some other different qualityadj (Anatomy) (of certain nerves, arteries, or veins) bending or curving around[C16: from Latin circumflexus, from circumflectere to bend around, from circum- + flectere to bend] ?circum?flexion nCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014cir?cum?flex (?s?r k?m?fl?ks) n. 1. a mark (^ or ~) placed over a vowel in some languages to indicate that the vowel is long, as in French, pronounced with a rise and fall in pitch, as in Classical Greek, stressed, or pronounced with a particular quality, as the (â) in (âr) air. adj. 2. a. consisting of, indicated by, or bearing a circumflex. b. pronounced with or characterized by the quality, length, stress, or pitch indicated by a circumflex. 3. bending or winding around. v.t. 4. to bend around. [1555?65;