SEXTANT, a sixth part of certain things. The Romans having divided their as into 12 ounces or uncia, the fifth part of that, or two ounces, was the sextans.—Sextans was also a measure which contained two ounces of liquor, or two cyatii.

astronomy, a constellation of the southern hemisphere, made by Hevelius out of unformed stars. In Hevelius's catalogue it contains 11, but in the Britannic catalogue 41 stars.