- axisaxis1 [ak′sis]n.pl. axes [ak′sēz΄] [L, axle, axis < IE * aks- < base * aĝ- (see ACT1) > OE eax, ON ǫxull, Gr axōn, L axilla]1. a real or imaginary straight line on which an object rotates or is regarded as rotating [the axis of a planet]2. a real or imaginary straight line around which the parts of a thing, system, etc. are symmetrically or evenly arranged or composed [the axis of a picture]3. a main line of motion, development, etc.4. an alignment between countries, groups, etc. for promoting their purposes5. Aeron. any of the three straight lines, perpendicular to each other, passing through the center of gravity of an aircraft, namely the longitudinal axis from nose to tail, the lateral axis from side to side, and the vertical axis from above to below6. Anat.a) the second cervical vertebrab) any of various axial or central parts7. Bot.a) the main stem of a plantb) the central system of a cluster8. Geom.a) a straight line through the center of a plane figure or solid, esp. one around which the parts are symmetrically arrangedb) a straight line for measurement or reference, as in a graph: see CARTESIAN COORDINATES9. Opticsa) a straight line through the centers of both surfaces of a lensb) a straight line from the object of vision to the fovea of the eye——————the Axisthe countries aligned against the Allies in WWII: originally applied to Nazi Germany and Fascist Italy (Rome-Berlin Axis), later extended to include Japan, etc. (Rome-Berlin-Tokyo Axis)axis2 [ak′sis]n.[ModL < L]any of a genus (Axis) of small deer of India and S Asia, with slender, sparsely branched antlers
English World dictionary. V. Neufeldt. 2014.