There are several explanations as to the meaning of the word “Omnibus”. First, as a noun, it is simply another word for what we call a bus, a large vehicle that carries many passengers, also referred to as coach or autobus. The word “Omnibus” contains the word “bus” and that’s exactly the main explanation of what an omnibus is. See also this British English explanatory video:
We also know “Omnibus” as a book (also noun). In that sense, an omnibus consists of a collection of books or articles by one single author or articles or books on the identical subject. You could speak of an omnibus of James Joyce’s works. and a Carol Oates omnibus would take up more space on your bookshelves than Shakespeare’s plays altogether.
Then there’s a third meaning of “Omnibus” (as an adjective). We also use the word when we want to describe something that’s covering many different subjects at the same time. We speak, for example, of an “Omnibus Bill” when relating to bills that have legislation about transportation, parking meters, or gun control.
So when we use “Omnibus”, we generally refer to something that’s complex and/or comprehensive. Let’s look at a few examples:
Omnibus (noun): a vehicle that can carry lots of passengers, often used for public transportation. Synonyms are a bus, autobus, motorbus, coach, motorcoach, passenger vehicle, double-decker.
There are several types of omnibuses. To give you some examples, the usual public transport public bus and the travel bus (coach), the minibus, a light bus that may carry up to 10 passengers, the school bus, used for the transportation of children from and to school, the trackless trolleybus, or trolley coach, an electric bus for carrying passengers that gets power from overhead wiring, and mail or freight buses, just to list a few.
Then we have the “Omnibus” as a collection of literary passages providing more things at once when it’s used as an adjective, like in “an omnibus law”. Synonyms, when used as an adjective, are comprehensive, and including all or everything
So as a noun, “Omnibus” can have the meaning of “several books together that were previously published separately but now in one volume”, like in “an omnibus of his first trilogy”; a bus, like in “a horse-drawn omnibus”, or as an adjective when including several items, like in “an omnibus edition of her novels”, a book that consists of at least two parts already published separately earlier. In the UK, “Omnibus” can also relate to a television program that consists of at least two parts that were broadcasted separately before, like in “that soap opera’s omnibus edition”.
Generally, when used as an adjective, “Omnibus” has little to do with the meaning as a bus for public transportation. The noun “Omnibus”, however, definitely does. It refers to what English speakers call “bus”. This is just the shortened word. The word “Omnibus” dates back to the 1820s when it was introduced into English from the French word that indicated a long, horse-drawn vehicle used to transport people along Paris’ main thoroughfares. It wasn’t long before the “Omnibus” was seen on the streets of New York.
In Latin, the word “Omnibus” means simply “for all” and the English adjective “omnibus” that was used from the mid-1800s, much resembles the original Latin meaning of the word “omnibus” though probably, the meaning of “omnibus” as a noun has had its influences. For example, when we speak of an “omnibus bill” (meaning it has numerous provisions), you don’t need much imagination to see the similarity with a bus full of people.
Let’s look at a few synonyms for “omnibus” as an adjective: all-in (mainly British English), all-embracing, all-inclusive, broad-gauged, broad-gauge, compendious, comprehensive, complete, cyclopedic, cover-all, embracive, full, exhaustive, encyclopedic, global, inclusive, thorough, universal, panoramic, in-depth.
In the world of insurance, the word “omnibus clause” refers to all residuary that are included but not specifically listed or mentioned. When talking about automobile liability insurance, an omnibus clause is common, for example. The omnibus clause covers not only the listed insured but also any household member as well as any person that uses the vehicle with the permission of the insured. We also see “omnibus clauses” commonly used in wills. This clause then distributes all not specifically named assets in the estate to the named beneficiary.