bolus
Concise Oxford English Dictionary © 2008 Oxford University Press:
bolus /ˈbəʊləs/
▶noun (pl. boluses)
- 1 a small rounded mass of a substance, especially of food being swallowed.
- 2 a large pill used in veterinary medicine.
■ Medicine a single dose of a drug given all at once.
– origin C16: via late L. from Gk bōlos ‘clod’.
'bolus' also found in these Oxford entries:

