umbra Meaning, Definition & Usage

  1. noun a region of complete shadow resulting from total obstruction of light

WordNet

Um"bra noun
Etymology
L., a shadow.
Wordforms
plural Umbræ
Definitions
  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. (Zoöl.) Any one of several species of sciænoid 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. J. Smith (Dict. Econ. Plants).

Webster 1913