Search the Dictionary

irm, fixed, or constant; subject to change or overthrow. -- Un*sta"ble*ness, n. Chaucer. Unstable equilibrium. See Stable equilibrium, under Stable.

An explosion or sudden report made by the instantaneous decomposition or combustion of unstable substances' as, the detonation of gun cotton.

Containing two equivalents of sulphur; as, dithionic acid. Dithionic acid (Chem.), an unstable substance, H2S2O6, known only in its solutions, and in certain well-defined salts.

parent assumption was that an Asian country with a Western orientation was as politically unstable as a domino standing on edge. Used by some as a justification for American involvement in the Vietnam war, 1964-1972.

aving different minds at different times; unsettled; undetermined. A double-minded man is unstable in all his ways. Jas. i. 8.

quirements; to be distinguished by superiority; as, to excel in mathematics, or classics. Unstable as water, thou shalt not excel. Gen. xlix. 4. Then peers grew proud in horsemanship t' excel. Pope.

Firmly fixed; closely adhering; made firm; not loose, unstable, or easily moved; immovable; as, to make fast the door. There is an order that keeps things fast. Burke.

Not fixed or firm; liable to change; unstable; of a changeable mind; not firm in opinion or purpose; inconstant; capricious; as, Fortune's fickle wheel. Shak. They know how fickle common lovers are. Dryden.

Infirm; unstable. "Firmless sands." Sylvester.

Full of fits; irregularly variable; impulsive and unstable. After life's fitful fever, he sleeps well. Shak. -- Fit"ful*ly, adv. -- Fit"ful*ness, n. The victorius trumpet peal Dies fitfully away. Macaulay.

To be unstable; to be easily or often moved. And the free soul to flitting air resigned. Dryden.

Unstable; fluttering. [Obs.] Dr. H. More.

Flowing; unstable; inconstant; variable. The flux nature of all things here. Barrow.

Not firm or solid; soft; unstable. Bacon.

Characterized by inconstancy; unstable; changeable; fickle; wild; thoughtless; heedless. "Giddy, foolish hours." Rowe. "Giddy chance." Dryden. Young heads are giddy and young hearts are warm. Cowper.

one thing to another without good reason; to have no settled purpose; to be irresolute or unstable. [Colloq.]

nd produced by a modified reduction of nitric acid. It is usually obtained as a volatile, unstable solution in water. It acts as a strong reducing agent.

m 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.

Not effectually guarded, protected, or sustained; unsafe; unstable; exposed to danger or loss. Bp. Hurg. The trade with Egypt was exceedingly insecure and precarious. Mickle.

The quality or condition of being unstable; want of stability, firmness, or steadiness; liability to give way or to fail; insecurity; precariousness; as, the instability of a building.