廃棄 （ハイキ） disposal, abandonment, scrapping, discarding, abolition, annulment, cancellation, abrogation, repeal

廃案 （ハイアン） rejected bill (project)

退廃 （タイハイ） (moral) decay, (social) decline, decadence, corruption, degeneration, deterioration, decline (in prosperity)

改廃 （カイハイ） reform and (or) abolition, alteration or repeal, revision, reorganization, reorganisation

廃れる （すたれる） to go out of use, to become obsolete, to die out, to go out of fashion, to go out of style, to decline (e.g. of morals), to be lost, to go into decline (of a town, business, etc.)

廃る （すたる） to go out of use, to become obsolete, to die out, to go out of fashion, to go out of style, to be hurt (of honour, reputation, etc.), to be harmed, to be sullied