dhidibka weyn ee ellipse ama ellipsoid waa dhexroorka ugu dheer, kaas oo dhex mara labada bar ee ugu fog ee soohdinta sawirka oo kala gooya bartamaha. Sidoo kale waa dhidibka u taagan dhidibka yar, kaas oo ah dhexroorka ugu gaaban ee dhex mara bartamaha ellipse ama ellipsoid. Joometri ahaan, dhidibka weyni waa fikrad muhiim ah oo loo isticmaalo in lagu qeexo qaabka iyo cabbirrada jaantusyada kala duwan ee joomatari, sida ellipses, ellipsoids, hyperbolas, iyo parabolas.