undulary adjective 2noun 1forms 3 adjective2 •Pertaining to the wave-like curve formed by the size of an ellipse as a function of the position of its focus.The undulary curve (fig. 2.6c) is formed by the focus of an ellipse rolling on the axis. — 2012 •(no longer used) Moving like waves; undulatory.yet do the blasts and undulary breaths thereof maintain no certainty in their course — 1672 noun1 •An undulary curve.An undulary can be expressed in parametric form using elliptic integrals. — 2012 formsundularies · more undulary · most undulary