carpenter's ovaln. a figure formed of two pairs of unequal circular arcs joined alternately where their tangents coincide, so as to form a continuous smooth closed curve, approximating an ellipse.
ΚΠ
1672 J. CollinsLet. in S. P. Rigaud & S. J. Rigaud Corr. Sci. Men 17th Cent. (1841) (modernized text) I. 201 Possibly they might not at London know one of the best ways of making a carpenter's oval to any ratio of diameters.