Grammar, an accent serving to note, or distinguish, a syllable of an intermediate sound between acute and grave; and generally somewhat long.—The Greeks had three accents, the acute, the grave, and the circumflex; formed thus, ἀ. In Latin, English, French, &c., the circumflex is made thus a.—The acute raises the voice, and the grave falls or lowers it: the circumflex is a kind of undulation, or wavering of the voice, between the two. It is seldom used among the moderns, unless to show the omission of a letter which made the syllable long and open; a thing much more frequent in the French than among us: thus they write pâte for pastè; tête for testè; flûmes for flusmes, &c. They also use the circumflex in the participles; some of their authors writing connuè, peu, others connuè, peu, &c. Father Buffier is at a loss for the reason of the circumflex on this occasion.

The form of the Greek circumflex was anciently the same with that of ours, viz. ἀ; being a composition of the other two accents ἀ in one.—But the copyists changing the form of the characters, and introducing the running hand, changed also the form of the circumflex accent; and instead of making a just angle, rounded it off, adding a dash, through too much haste; and thus formed an a, laid horizontally, which produced this figure, ἁ, instead of this ἀ.

Circumgyration, denotes the whirling motion of any body round a centre; such is that of the planets round the sun.