1.nounA navigational device for deriving angular distances between objects so as to determine latitude and longitude.
2.nounOne sixth of a circle or disc; a sector with an angle of 60°.
3.nounOne of six groups of adjacent teeth, excluding the wisdom teeth. The front sextants go from canine to canine, and there are sextants on the right and left of these. See w:Periodontal examination.