# bolus

/ˈboʊɫəs/ (US) · /bˈəʊləs/ (UK) · CEFR C2 · Noun

Source: https://englishreference.com/word/bolus
Updated: 2026-10-18

## Definition

a soft rounded lump of chewed food that you swallow in one go. Doctors also use it for a large dose of medicine given quickly at one time.

For teachers: a rounded mass of masticated food prepared in the mouth for swallowing. By extension, a single large dose of a drug or fluid administered rapidly to achieve an immediate physiological effect.

## Examples

- He swallows the bolus of rice in one gulp.
- The nurse gives the patient a bolus of saline through the IV to raise blood pressure quickly.
- After chewing, the tongue shapes the food into a bolus that slides down the throat, a process researchers study to understand swallowing disorders in elderly patients.

## Synonyms

lump, mouthful, dose

## Usage notes

- Plural is 'boluses' or 'boli'.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.