Chapter Hyponitrous to Hysterics of H by Webster's Dictionary (1913 Edition)

Hyponitrous to Hysterics

Hyponitrous
(Hy`po*ni"trous) a. [Pref. hypo- + nitrous.] (Chem.) Containing or derived from nitrogen having a lower valence than in nitrous compounds.

Hyponitrous acid (Chem.), an unstable nitrogen acid, NOH, whose salts are produced by reduction of the nitrates, although the acid itself is not isolated in the free state except as a solution in water; — called also nitrosylic acid.

Hypopharynx
(||Hy`po*phar"ynx) n. [NL. See Hypo-, and Pharynx.] (Zoöl.) An appendage or fold on the lower side of the pharynx, in certain insects.

Hypophosphate
(Hy`po*phos"phate) n. (Chem.) A salt of hypophosphoric acid.

Hypophosphite
(Hy`po*phos"phite) n. (Chem.) A salt of hypophosphorous acid.

Hypophosphoric
(Hy`po*phos*phor"ic) a. [Pref. hypo- + phosphoric.] (Chem.) Pertaining to, or derived from, or containing, phosphorus in a lower state of oxidation than in phosphoric compounds; as, hypophosphoric acid.

Hypophosphoric acid (Chem.), an acid, P₂H₄O₆, produced by the slow oxidation of moist phosphorus, and isolated only as a solution in water. It is regarded as a condensation product of one molecule of phosphoric acid with one of phosphorous acid, by partial dehydration.

Hypophosphorous
(Hy`po*phos"phor*ous) a. [Pref. hypo- + phosphorous.] (Chem.) Pertaining to, or containing, phosphorus in a lower state of oxidation than in phosphoric compounds; as, hypophosphorous acid.

Hypophosphorous acid (Chem.) , an acid, H₃PO₂, whose salts are produced by the action of barium hygrate on phosphorus. It may be obtained from its water solution, by exaporation and freezing, as a white crystalline substance. It is a powerful reducing agent.

Hypophyllous
(Hy*poph"yl*lous) a. [Pref. hypo- + Gr. leaf.] (Bot.) Being or growing on the under side of a leaf, as the fruit dots of ferns.

Hypophysial
(Hy`po*phys"i*al) a. (Anat.) Of or pertaining to the hypophysis; pituitary.

Hypophysis
(||Hy*poph"y*sis) n. [NL., fr. Gr. under + nature, origin.]

1. (Anat.) See Pituitary body, under Pituitary.

2. (Med.) Cataract.

Hypoplastron
(Hy`po*plas"tron) n.; pl. Hypoplastra [Pref. hypo- + plastron.] (Anat.) The third lateral plate in the plastron of turtles; — called also hyposternum.

Hypoptilum
(||Hy*pop"ti*lum) n.; pl. L. Hypoptila E. Hypoptilums [NL., fr. Gr. "ypo` beneath + down.] (Zoöl.) An accessory plume arising from the posterior side of the stem of the contour feathers of many birds; — called also aftershaft. See Illust. of Feather.

Hyporadius
(||Hy`po*ra"di*us) n.; pl. Hyporadii [Pref. hypo- + radius.] (Zoöl.) One of the barbs of the hypoptilum, or aftershaft of a feather. See Feather.

Hyporhachis
(||Hy`po*rha"chis) n.; pl. Hyporhachides [NL., fr. Gr. "ypo` beneath + spine.] (Zoöl.) The stem of an aftershaft or hypoptilum. [Written also hyporachis.]

Hyposkeletal
(Hy`po*skel"e*tal) a. [Pref. hypo- + skeletal.] (Anat.) Beneath the endoskeleton; hypaxial; as, the hyposkeletal muscles; — opposed to episkeletal.