Pl. areolæ. [L., dim. of ārea.] A very small area.
1. One of the small spaces marked out on a surface by intersecting lines, such as those between the veins of a leaf or the nervures of an insect’s wing.
1664. Power, Exp. Philos., I. 49. Pentagonal and hexagonal areola’s [on Corn Poppy seeds].
1830. Lindley, Nat. Syst. Bot., 313. A cluster of sporule-like areolæ of cellular tissue.
2. One of the interstices in the tissue of any organized substance.
1848. Quain, Elem. Anat. (1882), II. 107. The cell spaces in the calcified matrix [of bone] … being termed the primary areolæ.
1874. Van Buren, Dis. Urin. Org., 2. The areolæ of this tissue become distended with blood.
3. A circular spot; a colored circle such as that around the human nipple, and that which surrounds the vesicles or pustules in eruptive diseases.
1706. Phillips, Areola Papillaris, the Circle about a Nipple.
1852. W. Grove, Contrib. Sc., 365. Surrounded by a dusky and ill-defined areola.
1877. Roberts, Handbk. Med., I. 164. A faint red areola appears.
4. Biol. a. A slightly depressed spot on any surface. b. The cell-nucleus of a plant.
1862. Darwin, Orchids, v. 206. With a faint areola or nucleus visible.
1872. Nicholson, Palæont., 105. A round or oval smooth and excavated space which is termed the areola.
