semilunar

American  

[sem-ee-loo-ner, sem-ahy-] / ˌsɛm iˈlu nər, ˌsɛm aɪ- /

adjective

1. shaped like a half-moon; crescent.

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semilunar British  

/ ˌsɛmɪˈluːnə /

adjective

1. shaped like a crescent or half-moon

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Other Word Forms

• presemilunar adjective

Etymology

Origin of semilunar

First recorded in 1590–1600; semi- + lunar

Example Sentences

After blood passes through the pulmonary arteries, the right semilunar valves close preventing the blood from flowing backwards into the right ventricle.

From Textbooks • Jun. 9, 2022

There are three dilations in the wall of the aorta just superior to the aortic semilunar valve.

From Textbooks • Jun. 19, 2013

As ventricular pressure drops, there is a tendency for blood to flow back into the atria from the major arteries, producing the dicrotic notch in the ECG and closing the two semilunar valves.

From Textbooks • Jun. 19, 2013

When ventricular pressure rises above the pressure in the two major arteries, blood pushes open the two semilunar valves and moves into the pulmonary trunk and aorta in the ventricular ejection phase.

From Textbooks • Jun. 19, 2013

The semilunar valves of the pulmonary artery and aorta were unusually small, and their bases cartilaginous.

From Cases of Organic Diseases of the Heart by Warren, John Collins