Um"bra (?), n.; pl. Umbrae (#). [L., a shadow.]
1. Astron. (a)
The conical shadow projected from a planet or satellite, on the side opposite to the sun, within which a spectator could see no portion of the sun's disk; -- used in contradistinction from penumbra. See Penumbra.
(b)
The central dark portion, or nucleus, of a sun spot.
(c)
The fainter part of a sun spot; -- now more commonly called penumbra.
2. Zool.
Any one of several species of sciaenoid food fishes of the genus Umbrina, especially the Mediterranean species (U. cirrhosa), which is highly esteemed as a market fish; -- called also ombre, and umbrine.
Umbra tree Bot., a tree (Phytolacca diocia) of the same genus as pokeweed. It is native of South America, but is now grown in southern Europe. It has large dark leaves, and a somber aspect. The juice of its berries is used for coloring wine.
J. Smith (Dict. Econ. Plants).
© Webster 1913.