ALCYONOID
Al"cy*o*noid, a. Etym: [Gr. -oid.] (Zoöl.)
Defn: Like or pertaining to the Alcyonaria.
— n.
Defn: A zoöphyte of the order Alcyonaria.
ALDAY
Al"day, adv.
Defn: Continually. [Obs.] Chaucer.
ALDEBARAN Al*deb"a*ran, n. Etym: [Ar. al-debaran, fr. dabar to follow; so called because this star follows upon the Pleiades.] (Astron.)
Defn: A red star of the first magnitude, situated in the eye of
Taurus; the Bull's Eye. It is the bright star in the group called the
Hyades.
Now when Aldebaran was mounted high Above the shiny Cassiopeia's
chair. Spenser.
ALDEHYDE Al"de*hyde, n. Etym: [Abbrev. fr. alcohol dehydrogenatum, alcohol deprived of its hydrogen.] (Chem.)
Defn: A colorless, mobile, and very volatile liquid obtained from alcohol by certain of oxidation.
Note: The aldehydes are intermediate between the alcohols and acids, and differ from the alcohols in having two less hydrogen atoms in the molecule, as common aldehyde (called also acetic aldehyde or ethyl aldehyde), C2H4O; methyl aldehyde, CH2O. Aldehyde ammonia (Chem.), a compound formed by the union of aldehyde with ammonia.