Why was clemency trending last week?


[uhn-stey-buh l] /ʌnˈsteɪ bəl/
not stable; not firm or firmly fixed; unsteady.
liable to fall or sway.
unsteadfast; inconstant; wavering:
unstable convictions.
marked by emotional instability:
an unstable person.
irregular in movement:
an unstable heartbeat.
Chemistry. noting compounds that readily decompose or change into other compounds.
Origin of unstable
1175-1225; Middle English; see un-1, stable2
Related forms
unstableness, noun
unstably, adverb
2. precarious. 2, 3. See unsettled. 3. vacillating. Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
Cite This Source
Examples from the web for unstable
  • The two approaches, visual studies and art history, create a kind of unstable oil-and-water mixture in academic writing.
  • Sweet wines are alcoholic, fattening and unstable when transported.
  • These different forms of an element-called isotopes-are inherently stable or unstable.
  • Such abnormal hemoglobins often do not transport oxygen efficiently and may also be unstable.
  • But the markets are unstable and, bankers believe, increasingly tapped out.
  • Because they are made of ice, glacier caves can be quite unstable and present unique challenges to spelunkers.
  • They're overpopulated, their forests are gone and they're politically unstable.
  • At takeoff, the rocket is unstable and creates a pinwheel in the sky.
  • All this is difficult in countries with unstable politics and weak health systems, which is precisely where polio persists.
  • Kicks over millions of years can move an asteroid's orbit into an unstable area.
British Dictionary definitions for unstable


lacking stability, fixity, or firmness
disposed to temperamental, emotional, or psychological variability
(of a chemical compound) readily decomposing
  1. (of an elementary particle) having a very short lifetime
  2. spontaneously decomposing by nuclear decay; radioactive: an unstable nuclide
(electronics) (of an electrical circuit, mechanical body, etc) having a tendency to self-oscillation
Derived Forms
unstableness, noun
unstably, adverb
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source
Word Origin and History for unstable

early 13c., "apt to move," from un- (1) "not" + stable (adj.). Cf. Middle High German unstabel. Meaning "liable to fall" is recorded from c.1300; sense of "fickle" is attested from late 13c. An Old English word for this was feallendlic, which might have become *fally.

Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
unstable in Science
  1. Liable to undergo spontaneous decay into some other form. For example, the nucleus of uranium 238 atom is unstable and changes by radioactive decay into the nucleus of thorium 234, a lighter element. Many subatomic particles, such as muons and neutrons, are unstable and decay quickly into other particles. See more at decay.

  2. Relating to a chemical compound that readily decomposes or changes into other compounds or into elements.

  3. Relating to an atom or chemical element that is likely to share electrons; reactive.

  4. Characterized by uncertain or inadequate response to treatment and the potential for unfavorable outcome, as the status of a medical condition or disease.

The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source

Word of the Day

Difficulty index for unstable

Most English speakers likely know this word

Word Value for unstable

Scrabble Words With Friends

Quotes with unstable

Nearby words for unstable