The word omnibus is French, from Latin origins. Omni means "for all," or "all." It is part of a French motto, "Omnes Omnibus," meaning "all for all." Its first use leading to the form it is used in today was "voiture omnibus," meaning "carriage for all."
As omnibus often refers to a large bus or other means of transportation capable of moving several people at one time. The omnibus as a means for transportation originated in Europe in the early nineteenth century. The term omnibus as a way to describe transportation for large numbers of people later traveled to England as well as New York in the United States. Today an omnibus describes any large bus service. In fact, the more common word "bus" is merely a shortened form of the original term.
Omnibus as a noun can also refer to a collection of reprinted works. These works are either written by a single author or collectively represent a singular theme or interest. This collection is then typically published in book form. Popular comics often print an omnibus edition focusing on a single character.
The word omnibus can also be used as an adjective and in this form often describes a bill or other legislation. An omnibus bill is a piece of legislation requiring only a single vote, but which will pass numerous amendments to a law, or multiple laws. Combined appropriation bills and reconciliation bills are both examples of omnibus bills.
Omnibus as an adjective in another context simply means encompassing many things at once or relating to many things at once. For example, an omnibus survey covers a variety of topics. However, this form of the word is much less common. In most cases, omnibus is used as a noun.