NE om "kvadrant":

kvadrant (lat. qua´drans 'fjärdedel', av qua´dro eg. 'göra fyrkantig') 1 sektor som upptar ett fjärdedels varv (90°). Kvadranter kallas även de fyra delar i vilka planet delas av koordinataxlarna i ett koordinatsystem.

Merriam Webster om "quadrant":

1 : something shaped like a quarter-circle: as a : an instrument for measuring altitudes variously constructed and mounted for different specific uses (as in astronomy, surveying, gunnery) and consisting commonly of a graduated arc of 90* with an index or vernier and either plain or telescopic sights and usually having a plumb line or spirit level for fixing the vertical or horizontal direction b : a device resembling a bell crank for converting the horizontal reciprocating motion of an engine piston rod into the vertical up-and-down movement of a pump rod c : a dial or an indexing sector of approximate quarter-circle range; also : a lever that moves over such a range d : a device on a spinning mule for controlling the winding of the yarn

2 a : a quarter of a circle, an arc of 90*, or an arc subtending a right angle at the center b : the area bounded by a quadrant and two radii
3 a : any of the four parts into which a plane is divided by rectangular coordinate axes lying in that plane b : any of the four more or less equal parts into which something is divided by two real or imaginary lines that intersect each other at right angles *located in the upper left quadrant of a page* *a building in the southeast quadrant of the city* *most hurricanes T are not symmetrical * the winds are much stronger in some quadrants R.C.Gentry & R.H.Simpson* c : a group comprising all the cells resulting from divisions of one of the first four blastomeres in spirally cleaving eggs with determinate cleavage d : any of four more or less equivalent segments into which an anatomic structure or surface may be divided by vertical and horizontal partitioning through its midpoint used chiefly of the abdomen *severe pain in the lower right quadrant* e : the sector between the equisignal zones of a four-course aural radio range

Min andra referens nedan kan nog vara till hjälp om du vill jaga tandvårdstermer på engelska.