Any small circular area that is different from its immediate environment such as the colored ring around the pupil of the eye (iris) or an inflamed region surrounding a pimple
small circular area such as that around the human nipple or an inflamed area around a pimple or insect bite small space in a tissue or part such as the area between veins on a leaf or an insect's wing
An interstice or small space, as between the cracks of the surface in certain crustaceous lichens; or as between the fibers composing organs or vessels that interlace; or as between the nervures of an insect's wing