Emily Dickinson Lexicon

SEX'TANT, n. [L. sextans, a sixth. The Romans divided the as into 12 ounces; a sixth, or two ounces, was the sextans.]

1. In mathematics, the sixth part of a circle. Hence,
2. An instrument formed like a quadrant, excepting that its limb comprehends only 60 degrees, or the sixth part of a circle. – Encyc.
3. In astronomy, a constellation of the southern hemisphere, which, according to the British catalogue, contains 41 stars. Encyc.