The Collaborative International Dictionary of English v.0.48:
Umbrella \Um*brel"la\, n. [It. ombrella, fr. ombra a shade, L.
umbra; cf. L. umbella a sunshade, a parasol. Cf. Umbel,
1. A shade, screen, or guard, carried in the hand for
sheltering the person from the rays of the sun, or from
rain or snow. It is formed of silk, cotton, or other
fabric, extended on strips of whalebone, steel, or other
elastic material, inserted in, or fastened to, a rod or
stick by means of pivots or hinges, in such a way as to
allow of being opened and closed with ease. See Parasol.
Underneath the umbrella's oily shed. --Gay.
2. (Zool.) The umbrellalike disk, or swimming bell, of a
3. (Zool.) Any marine tectibranchiate gastropod of the genus
Umbrella, having an umbrella-shaped shell; -- called
also umbrella shell.
Umbrella ant (Zool.), the sauba ant; -- so called because
it carries bits of leaves over its back when foraging.
Called also parasol ant.
Umbrella bird (Zool.), a South American bird
(Cephalopterus ornatus) of the family Cotingidae. It
is black, with a large and handsome crest consisting of a
mass of soft, glossy blue feathers curved outward at the
tips. It also has a cervical plume consisting of a long,
cylindrical dermal process covered with soft hairy
feathers. Called also dragoon bird.
Umbrella leaf (Bot.), an American perennial herb
(Dyphylleia cymosa), having very large peltate and lobed
Umbrella shell. (Zool.) See Umbrella, 3.
Umbrella tree (Bot.), a kind of magnolia (Magnolia
Umbrella) with the large leaves arranged in umbrellalike
clusters at the ends of the branches. It is a native of
Pennsylvania, Virginia, and Kentucky. Other plants in
various countries are called by this name, especially a
kind of screw pine (Pandanus odoratissimus).
[1913 Webster] Umbrere