Mathematics. The axis of symmetry of a conic which passes through the foci; the transverse axis. Contrasted with conjugate axis.

(a) an axis transverse to the main axis, as in a crystal; (b) Geometry the axis passing through the foci of a conic section (in an ellipse, the major…

Something that is transverse: spec. The transverse axis of a conic section.

the long axis of an object or structure (long axis n. at long, adj.1 n.1compounds 4a); spec. an axis running the length of a craft or vehicle…

(a) Geometry the line passing through the focus or foci of a conic section, perpendicular to the directrix; (b) Optics the line which passes…

the axis of a conic section, which passes through the foci, esp. the longer axis of an ellipse; also called principal axis, transverse axis.