This means that the bill is now rejected and won't continue to be considered.
What is the bill's main idea?
The purpose of this bill is to make it possible for the government to hold a national plebiscite to ask Australians "Should the law be changed to allow same-sex couples to marry?"
What is a national plebiscite?
The bills digest explains that:
a national plebiscite is a vote by citizens on any subject of national significance but which does not affect the Constitution. Plebiscites are normally advisory and do not compel a government to act on the outcome. There have only been three national plebiscites—two on conscription during World War I (both defeated) and one on the choice of a National Song in 1977.