throw over

verb2

1. •
   To discard or give up (a plan or project, etc.).

   • I failed to strike anything of any benefit at all, and I became entirely disgusted and threw the whole thing over. — 1909
2. •
   To break off relations with (a friend, romantic partner etc.).

   • The girl he was engaged to at Clapton Hill tried to get it out of him, and threw him over partly because he refused, and partly because, as she said, he fairly gave her the "'ump." — 1901