bolus
UK[ˈbəʊləs]US[ˈboʊləs]
n
a small rounded mass of a substance, especially of chewed food at the moment of swallowing.
n
a single, relatively large quantity of a substance, such as a drug, given intravenously over a short period.
Etymology
The term 'bolus' entered english in the 17th century directly from modern latin, where it meant 'rounded mass'. This latin term was itself a borrowing from the ancient greek word 'βῶλος' (bôlos), which carried the same meaning of a clod, lump, or ball of earth. The semantic journey is remarkably direct, moving from the concrete image of a clod of soil in ancient greek to its specialized medical and biological applications today, describing a cohesive mass of food or a concentrated dose of medicine. This evolution highlights how a simple, literal descriptor for a physical shape was adopted into scientific terminology to name specific, functionally similar forms.
Analysis
the word is a simplex loanword; it cannot be meaningfully segmented into smaller morphemes using its current english spelling.
Examples
the patient was instructed to swallow the barium bolus for the x-ray.
the nurse administered an intravenous bolus of antibiotics.
after thorough chewing, the food forms a bolus that is ready to be propelled down the esophagus.