a. [ L. extans, -antis, or exstans, -antis, p. pr. of extare, exstare, to stand out or forth; ex out + stare to stand: cf. F. extant. See Stand. ] 1. Standing out or above any surface; protruded. [ 1913 Webster ]

That part of the teeth which is extant above the gums. Ray. [ 1913 Webster ]

A body partly immersed in a fluid and partly extant. Bentley. [ 1913 Webster ]

2. Still existing; not destroyed or lost; outstanding. [ 1913 Webster ]

Writings that were extant at that time. Sir M. Hale. [ 1913 Webster ]

The extant portraits of this great man. I. Taylor. [ 1913 Webster ]

3. Publicly known; conspicuous. [ Obs. ] B. Jonson. [ 1913 Webster ]

adj. No longer existing; inaccessible through loss or destruction. [ WordNet 1.5 ]

Its nonextant original was written on vellum G. B. Saul

n. [ L. sextans, -antis, the sixth part of an as, fr. sextus sixth, sex six. See Six. ] 1. (Math.) The sixth part of a circle. [ 1913 Webster ]

2. An instrument for measuring angular distances between objects, -- used esp. at sea, for ascertaining the latitude and longitude. It is constructed on the same optical principle as Hadley's quadrant, but usually of metal, with a nicer graduation, telescopic sight, and its arc the sixth, and sometimes the third, part of a circle. See Quadrant. [ 1913 Webster ]

3. (Astron.) The constellation Sextans. [ 1913 Webster ]

Box sextant, a small sextant inclosed in a cylindrical case to make it more portable. [ 1913 Webster ]