A small part of an artery leading to a capillary. The oxygenated hemoglobin (oxyhemoglobin) helps make the blood in arterioles (and arteries) look bright red.
"tiny artery," by 1808, from Modern Latin arteriola, diminutive of arteria (see artery).
one of the small thin-walled arteries that result in capillaries
- a little artery.
(n.) A small artery.