Pear (pâr), n. [OE. pere,
AS. peru, L. pirum: cf. F. poire. Cf.
Perry.] (Bot.) The fleshy pome, or fruit, of a
rosaceous tree (Pyrus communis), cultivated in many varieties
in temperate climates; also, the tree which bears this fruit. See
Pear family, below.
Pear blight. (a) (Bot.)
A name of two distinct diseases of pear trees, both causing a
destruction of the branches, viz., that caused by a minute insect
(Xyleborus pyri), and that caused by the freezing of the sap in
winter. A. J. Downing. (b)
(Zoöl.) A very small beetle (Xyleborus pyri)
whose larvæ bore in the twigs of pear trees and cause them to
wither. -- Pear family (Bot.), a
suborder of rosaceous plants (Pomeæ), characterized by
the calyx tube becoming fleshy in fruit, and, combined with the
ovaries, forming a pome. It includes the apple, pear, quince, service
berry, and hawthorn. -- Pear gauge
(Physics), a kind of gauge for measuring the exhaustion of
an air-pump receiver; -- so called because consisting in part of a
pear-shaped glass vessel. -- Pear shell
(Zoöl.), any marine gastropod shell of the genus
Pyrula, native of tropical seas; -- so called from the
shape. -- Pear slug (Zoöl.),
the larva of a sawfly which is very injurious to the foliage of
the pear tree.