annular
Forming a circle
Annular means ring-shaped or forming a ring.
An annular eclipse occurs when the moon covers the sun's center but leaves a bright ring visible around the edges.
The term appears in technical contexts—anatomy, engineering, astronomy—wherever ring structures matter: the annular ligament, an annular seal.
Doughnut-shaped solid
- ringClosed curve shape
- hoopRigid circular frame
- diskFlat circular object
- washerSpacer ring for fasteners
gasket · doughnut · circlet · band · collar · flange · sleeve · bearing
Circle's outer measurement
- perimeterShape's outer edge length
- radiusCenter-to-perimeter distance
- diameterDistance across through center
- concentricSharing one center
coaxial · cylindrical · toroidal · arc · curvature · inner · outer · cross-section
Star's outermost atmosphere
- umbraComplete shadow region
- penumbraRegion of partial illumination
- totalityComplete aggregate amount
- partialFavoring one side
solar · lunar · syzygy · occultation · transit · phase · celestial · astronomy
torus
Doughnut-shaped solid
washer · gasket · doughnut · circlet · band · collar · flange · sleeve · bearing · seal
circumference
Circle's outer measurement
- perimeterShape's outer edge length
- radiusCenter-to-perimeter distance
- diameterDistance across through center
concentric · coaxial · cylindrical · toroidal · arc · curvature · inner · outer · cross-section · area
corona
Star's outermost atmosphere
partial · solar · lunar · syzygy · occultation · transit · phase · celestial · astronomy · telescope
helix
Spiraling three-dimensional curve
volute · scroll · convolute · winding · helical · cochlea · nautilus
phalanges
Bones of fingers, toes