arcus

Meaning

1. A white band of cholesterol that forms at the edge of the cornea
2. A low, horizontal cloud typically forming at the leading edge of thunderstorm outflow
3. An elastic band around the base of the arolium, a pad at the end of the leg of certain insects
4. An arc-shaped band of thickened sexine extending between two apertures on a pollen grain or spore

Synonyms

arcus senilis

arc

arch

bow

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Etymology

Borrowed from Latin arcus. Doublet of arc and arco. Distantly related to arrow.