annulus — meaning in English
Dutch → English · translate English → Dutch instead
English meaning
- annulus noun A ring- or donut-shaped area, object, or structure.
Senses
annulus is used for these senses in English:
- annulus (botany) A structure surrounding a sporangium (or part of it) which shrinks and causes it to rupture for spore dispersal; specifically, in a fern: a structure around about two-thirds of the sporangium consisting of differentially thick-walled cells which dry and distort the sporangium; and in a moss: a complete ring of cells around the tip of the sporangium which dissolves to cause the tip to detach.
annulus — full definition
- noun A ring- or donut-shaped area, object, or structure.
- noun A ring of fibrous tissue; specifically (cardiology), such a ring around an opening of a heart valve, to which the valve leaflets and muscle fibres of the atria and ventricles are attached; an annulus fibrosus cordis.
- noun A ring of light in a celestial body, especially when caused by an annular eclipse (for example, when the Sun and Moon are in line with the Earth, but the Moon does not completely cover the Sun's disc).
- noun A structure surrounding a sporangium (or part of it) which shrinks and causes it to rupture for spore dispersal; specifically, in a fern: a structure around about two-thirds of the sporangium consisting of differentially thick-walled cells which dry and distort the sporangium; and in a moss: a complete ring of cells around the tip of the sporangium which dissolves to cause the tip to detach.