Omnibus bill

An omnibus bill is a proposed law that covers a number of diverse or unrelated topics. "Omnibus" is derived from Latin and means "to, for, by, with or from everything". An omnibus bill is a single document that is accepted in a single vote by a legislature but packages together several measures into one or combines diverse subjects.
Because of their large size and scope, omnibus bills limit opportunities for debate and scrutiny. Historically, omnibus bills have sometimes been used to pass controversial amendments. For this reason, some consider omnibus bills to be anti-democratic.
United States.
In the United States, omnibus bills are sometimes known as "Big Ugly" bills. Examples include reconciliation bills, combined appropriations bills, and private relief and claims bills.
Appropriations legislation.
Omnibus legislation is routinely used by the United States Congress to group together the budgets of all departments in one year in an omnibus spending bill. For example, the Omnibus Budget Reconciliation Act of 1993 was designed to help reduce the federal deficit by approximately $496 billion over five years through restructuring of the tax code.
Historical examples.
During the 19th century, there were three notable omnibus bills.
The Compromise of 1850 had five disparate provisions designed by Senator Henry Clay of Kentucky. His purpose was to pacify sectional differences that threatened to provoke the secession of the slave states. The Fugitive Slave Act was the most infamous of the five compromise components, and was almost universally excoriated by abolitionists, the chief exception being Sen. Daniel Webster of Massachusetts who prioritized preservation of the Union. Senator Thomas Hart Benton, a Missouri slaveholder, opposed the omnibus compromise as an "unmanageable mass of incongruous bills, each an impediment to the other..." While this bill did not pass as the official Compromise of 1850, it got the ball rolling. To satisfy members of Congress, Stephen A Douglas separated the Compromise back into 5 separate bills and got it passed. Ultimately, disunion and civil war were delayed for a decade. In response, the 1861 Constitution of the Confederate States would ban omnibus legislation, requiring that every bill "shall relate to but one subject, and that shall be expressed in the title" (Article 1, Section 9.20). 
The Omnibus Act of June 1868 admitted seven southern U.S. states as having satisfied the requirements of the Reconstruction Acts.
The Omnibus Act of February 22, 1889 provided for the admission of four new states to the Union — North Dakota, South Dakota, Montana and Washington.
Canada.
In Canada one famous omnibus bill became the Criminal Law Amendment Act, 1968–69, a 126-page, 120-clause amendment to the Criminal Code passed under the leadership of Pierre Elliot Trudeau who was then Justice Minister in the government of Lester Pearson. This Act changed the law of the land in matters as diverse as homosexuality, prostitution, abortion, gambling, gun control and drunk driving.
Likewise, Jobs and Growth Act (2012).
The SNC-Lavalin affair, which entailed the censure of Justin Trudeau by the Parliamentary Ethics Commissioner, was started when the firm suggested to Trudeau that he include in his spring 2018 budget bill the deferred prosecution agreement measure that then-Attorney-General Wilson-Raybould refused to sanction, culminating in her January 2019 ouster from government and the subsequent scandal that surrounded it.
The Greenhouse Gas Pollution Pricing Act was created during the 42nd Parliament of Canada under the mask of the Budget Implementation Act, 2018, No. 1 in "Part 4". The SNC-Lavalin affair was created as "Division 20 of Part 6".
Other countries.
In the Republic of Ireland, the Second Amendment of the Constitution was an omnibus constitutional law, enacted in 1941, that made many unrelated changes to the country's fundamental law.
In Serbia, Omnibus law was adopted in 2002 that regulated the autonomous status of Vojvodina.
Similarly, in New Zealand, an omnibus bill was passed in November 2016 that enacted legislation required for New Zealand to enter the Trans Pacific Partnership.
Section 55 of the Constitution of Australia requires that laws imposing taxation "deal only with the imposition of taxation" and "deal with one subject of taxation only" (except those relating to customs and excise); other purported provisions in a piece of tax legislation are of no legal effect. This does not outlaw all omnibus bills, but renders unconstitutional any omnibus bill imposing taxation.
In October 2020, the People's Representative Council of Indonesia passed the Omnibus Law on Job Creation, a controversial omnibus law that aims to attract foreign investment and reduce business regulation, which the opponents say would be harmful to the environment and threaten labor rights in existing law. This caused nationwide protests and riots involving workers and students.