And the urchins that stand with their thievish eyes Forever on watch
ran off each with a prize.
W. Howitt.
You did indeed dissemble, you urchin you; but where's the girl that
won't dissemble for an husband?
Goldsmith.
5. One of a pair in a series of small card cylinders, arranged around a
carding drum; — so called from its fancied resemblance to the hedgehog.
Knight.
Urchin fish (Zoöl.), a diodon.
Ur"chin, a. Rough; pricking; piercing. [R.] "Helping all urchin
blasts." Milton.
Ur"chon (?), n. (Zoöl.) The urchin, or hedgehog.
Ur"du (?), n. [Hind. urd.] The language more generally called
Hindustanee.
Ure (?), n. [OE. ure, OF. oevre, ovre, ouvre, work, F. œuvre, L. opera.
See Opera, Operate, and cf. Inure, Manure.] Use; practice; exercise.
[Obs.] Fuller.
Let us be sure of this, to put the best in ure That lies in us.
Chapman.
Ure, v. t. To use; to exercise; to inure; to accustom by practice.
[Obs.]
The French soldiers . . . from their youth have been practiced and ured
in feats of arms.
Sir T. More.
U"re*a (?), a. [NL. See Urine.] (Physiol. Chem.) A very soluble
crystalline body which is the chief constituent of the urine in mammals
and some other animals. It is also present in small quantity in blood,
serous fluids, lymph, the liver, etc.
It is the main product of the regressive metamorphosis (katabolism) of
proteid matter in the body, and is excreted daily to the amount of
about 500 grains by a man of average weight. Chemically it is
carbamide, CO(NH2)2, and when heated with strong acids or alkalies is
decomposed into carbonic acid and ammonia. It unites with acids to form
salts, as nitrate of urea, and it can be made synthetically from
ammonium cyanate, with which it is isomeric.
Urea ferment, a soluble ferment formed by certain bacteria, which,
however, yield the ferment from the body of their cells only after they
have been killed by alcohol. It causes urea to take up water and
decompose into carbonic acid and ammonia. Many different bacteria
possess this property, especially Bacterium ureæ and Micrococcus ureæ,
which are found abundantly in urines undergoing alkaline fermentation.
U"re*al (?), a. Of or pertaining to urea; containing, or consisting of,
urea; as, ureal deposits.
U`re*am"e*ter (?), n. [Urea + - meter.] (Physiol. Chem.) An apparatus
for the determination of the amount of urea in urine, in which the
nitrogen evolved by the action of certain reagents, on a given volume
of urine, is collected and measured, and the urea calculated
accordingly.
U`re*chi"tin (?), n. (Chem.) A glucoside extracted from the leaves of a
certain plant (Urechitis suberecta) as a bitter white crystalline
substance.
U`re*chi*tox"in (?), n. [Urechitin + toxic + -in.] (Chem.) A poisonous
glucoside found accompanying urechitin, and extracted as a bitter white
crystalline substance.
||U*re"do (?), n. [L., a blast, blight, a burning itch, fr. urere to
||burn, to scorch.]
||
1. (Bot.) One of the stages in the life history of certain rusts
(Uredinales), regarded at one time as a distinct genus. It is a summer
stage preceding the teleutospore, or winter stage. See Uredinales, in
the Supplement.