Fr.: ellipse d'aberration
The locus of a point the sum of whose distances from two fixed points is constant.
From O.Fr. ellipse, from L. ellipsis "ellipse," also, "a falling short, deficit," from Gk. elleipsis "an omission," from el-, variant of en-, + leip-, stem of leipein "to leave" + suffix -sis.
Beyzi, from Ar.
Fr.: ellipse de parallaxe
The path on the sky of the apparent position of a star as seen from the Earth, due to the Earth's annual motion around the Sun.