what is nova
Definition of NOVA. : a star that suddenly increases its light output tremendously and then fades away to its former obscurity in a few months or years.â noÂ·vaÂ·like \-vÉ-ËlÄ«k\ adjective.ADVERTISEMENT.efinition of NOVA. : a star that suddenly increases its light output tremendously and then fades away to its former obscurity in a few months or years. â noÂ·vaÂ·like \-vÉ-ËlÄ«k\ adjective. ADVERTISEMENT.