all at once, together Adv. [Probably a reduplication of bolus* or of whole with Latin endings].
the whole. n.
--Webster’s New International Dictionary Second Edition Unabridged.
Altogether; all at once.
Etymology: 19c: sham Latin, based on whole bolus.
* What is a bolus? Bolus: (1) a rounded mass of anything, as a large pill, such as those used in veterinary practice, or a soft mass of chewed food ready to be swallowed. or (2) a Bole, a [brown reddish yellow] clay.
--Webster’s New International Dictionary Second Edition Unabridged
Bloggin' John Comments:
Holus-bolus is an example of sham Latin, the adding of a Latin ending (-us) to a non-Latin root (bole). The motive for constructing sham Latin is pure fun--the fun in seeing the root of a "lesser" language dressed up in front or back or both as if it were truly a lofty Latin word.
•In Weird Words Berent and Evans define holus-bolus as “all at one time” and offer the following sentence in which the word is used as an adverb:
“He said that he wanted to complete the project holus-bolus rather than doing it in stages over a period of months.”
Bloggin’ John Comments:
Once we know what a bole is—i.e. a tightly compressed lump of brown reddish clay or a masticated blob of a Big Mac bite lolling in the mouth prior to sliding down the esophagus—we can begin to see how much fun is packed into this word. Some playful user of English around 1850, with tongue firmly in cheek, added to bolus the reassuring, gratuitous notion that the mass of the object under discussion is developed to its fullest quantity or extent by prefacing bolus with a word that sounds like whole, holus, creating a rhyme, no less, in the process. Now the original word was twice its original size, and freighted, so to speak, with inflated meaning. To complete the joke, the word is tricked out in sham Latin, twice, using the suffix -us, thus adding further conceptual inflation buy insinuating that the word is of Latin origin.
•Here’s holus-bolus used as a noun: “Use that tarp over there to wrap all of the raked leaves into one big holus-bolus.”
And here it is used as an adverb:
THAI TALK: Tarrin fell holus-bolus for 'side letters' trap.
--The Nation (Thailand); Author: Suthicai Yoon; February 10, 1999.
--HighBeam Research, Inc.
Note that holus-bolus in a compound that by convention takes a hyphen between its two elements: holus-bolus.