bolus

noun

bo·​lus ˈbō-ləs How to pronounce bolus (audio)
plural boluses
Synonyms of bolusnext
1
: a rounded mass: such as
a
: a large pill
b
: a soft mass of chewed food
2
medical
a
: a dose of a substance (such as a drug) given intravenously
b
: a large dose of a substance given by injection for the purpose of rapidly achieving the needed therapeutic concentration in the bloodstream

Examples of bolus in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Could infusing an extra bolus of these cells do more harm than good? — Byjennifer Couzin-Frankel, science.org, 14 Nov. 2024 Unlike human pesticides, though, termite boluses were not lethal to the weed. — ArsTechnica, 10 Oct. 2025 Mazlish watched as his wife programmed her insulin pump to deliver both dribbles of basal insulin throughout the day and a large bolus with meals. — Carrie Arnold, Scientific American, 14 Oct. 2025 There, he was prescribed brimhana, or tissue regeneration, using a bolus therapy made from goat meat mixed with rice, milk, and spices. — Mark Ellwood, Robb Report, 14 Feb. 2026 See All Example Sentences for bolus

Word History

Etymology

Late Latin, from Greek bōlos lump

First Known Use

1562, in the meaning defined at sense 1

Time Traveler
The first known use of bolus was in 1562

Phrases Containing bolus

Rhymes for bolus

See All Rhymes for bolus

Browse Nearby Words

Boltzmann equation
bolus
bolus alba
See all Nearby Words

Cite this Entry

“Bolus.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/bolus. Accessed 7 Jul. 2026.

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Medical Definition

bolus

noun
bo·​lus ˈbō-ləs How to pronounce bolus (audio)
plural boluses
1
: a rounded mass: as
a
: a large pill
b
: a soft mass of chewed food
2
a
: a dose of a substance (as a drug) given intravenously
b
: a large dose of a substance given by injection for the purpose of rapidly achieving the needed therapeutic concentration in the bloodstream
the patient receives a bolus dose to reach the minimum effective analgesic concentration—J. F. Camp
subcutaneous injection of a premeal bolus of fast-acting insulin

More from Merriam-Webster on bolus

Thesaurus: All synonyms and antonyms for bolus

Nglish: Translation of bolus for Spanish Speakers

Britannica.com: Encyclopedia article about bolus

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