annulus
/ˈænjələs/
noun
- A ring-shaped object, structure, or area.
- A smoke ring is a type of annulus that floats through the air.
- The engineer designed a metal annulus to support the pipe joint.
- The tree's growth rings form an annulus visible in the cross-section.
- In mathematics, the region between two concentric circles.
- The area of an annulus is found by subtracting the area of the inner circle from the outer circle.
- A washer is a real-world example of an annulus.
- Students calculated the width of the annulus given the radii of both circles.
- In biology, a ring-like part or marking on an organism, such as on a worm or a mushroom stem.
- The annulus on the mushroom's stem helps identify the species.
- The biologist noted the annulus pattern on the fish's scales.
- Earthworms have a visible annulus called the clitellum near their front end.