Real Dictionary

circumflex
countable noun: A circumflex or a circumflex accent is a symbol written over a vowel in French and other languages, usually to indicate that it should be pronounced longer than usual. It is used for example in the word 'rôle'.

circumflex in American English
a mark (^ or ˜) used over certain vowel letters in the orthography of some languages to indicate a specific sound or quality, or used in certain systems of symbols for representing speech sounds: in modern use, as in French, the form (^) is the most commo
adjective: consisting of, indicated by, or bearing the mark ˆ, ˘, or ~, placed over a vowel symbol in some languages to show that the vowel or the syllable containing it is pronounced in a certain way, as, in French, that the vowel so marked is of a certain quality
noun: a circumflex mark or accent
transitive verb: to bend around

circumflex in British English
adjective: (of certain nerves, arteries, or veins) bending or curving around
noun: 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 quality