unstable
adjective
un·sta·ble
ˌən-ˈstā-bəl 
: not stable : not firm or fixed : not constant: such as
a
: not steady in action or movement : irregular
an unstable pulse
b
: wavering in purpose or intent : vacillating
c
: lacking steadiness : apt to move, sway, or fall
an unstable tower
d(1)
: liable to change or alteration
an unstable economy
unstable weather
(2)
: readily changing (as by decomposing) in chemical or physical composition or in biological activity
e
: characterized by lack of emotional control
unstableness
noun
Examples of unstable in a Sentence
an unstable nuclear reactor core
the minute we put the books down on the unstable desk, the whole stack went crashing to the floor
Recent Examples on the Web
The series of thunderstorms moving northward into the region, pushed along by a boundary of unstable air, will approach the I-20 corridor as early as 3-4 p.m. Monday.
—
David Montesino, Fort Worth Star-Telegram, 9 Apr. 2024
Russian sales are becoming ever more important for Chinese manufacturers, given unstable domestic demand in China and decreasing exports to traditional markets in the West.
—Alexander Gabuev, Foreign Affairs, 9 Apr. 2024
Suddenly, anyone who had a period was seen as unstable.
—Shalene Gupta, TIME, 4 Apr. 2024
For prospective corporate offset buyers, the marketplace appears opaque and unstable.
—Lydia Depillis, New York Times, 4 Apr. 2024
National Weather Service / National Oceanic and Atmospheric Administration
Meteorologists also warned that eastern Virginia and the upper part of North Carolina could be hit with strong thunderstorms on Wednesday afternoon, as a band of unstable weather gradually spreads southeastward.
—Emily Mae Czachor, CBS News, 3 Apr. 2024
In an unstable world, stability has become the hallmark of a good employer, but a truly great place to work also offers flexibility and a healthy respect for individuality to boot.
—Chloe Berger, Fortune, 4 Apr. 2024
Analysis by severe weather expert Jeff Halverson A stubborn wedge of chilly, rainy air may be invaded and eroded by a southerly push of milder, more unstable air, ahead of an approaching cold front.
—Jeff Halverson, Washington Post, 3 Apr. 2024
Instead, Haiti is the hemisphere’s most unstable country and its poorest.
—Jacqueline Charles, Miami Herald, 2 Apr. 2024
David Montesino, Fort Worth Star-Telegram, 9 Apr. 2024
Russian sales are becoming ever more important for Chinese manufacturers, given unstable domestic demand in China and decreasing exports to traditional markets in the West.
—Alexander Gabuev, Foreign Affairs, 9 Apr. 2024
Suddenly, anyone who had a period was seen as unstable.
—Shalene Gupta, TIME, 4 Apr. 2024
For prospective corporate offset buyers, the marketplace appears opaque and unstable.
—Lydia Depillis, New York Times, 4 Apr. 2024
National Weather Service / National Oceanic and Atmospheric Administration
Meteorologists also warned that eastern Virginia and the upper part of North Carolina could be hit with strong thunderstorms on Wednesday afternoon, as a band of unstable weather gradually spreads southeastward.
—Emily Mae Czachor, CBS News, 3 Apr. 2024
In an unstable world, stability has become the hallmark of a good employer, but a truly great place to work also offers flexibility and a healthy respect for individuality to boot.
—Chloe Berger, Fortune, 4 Apr. 2024
Analysis by severe weather expert Jeff Halverson A stubborn wedge of chilly, rainy air may be invaded and eroded by a southerly push of milder, more unstable air, ahead of an approaching cold front.
—Jeff Halverson, Washington Post, 3 Apr. 2024
Instead, Haiti is the hemisphere’s most unstable country and its poorest.
—Jacqueline Charles, Miami Herald, 2 Apr. 2024
These examples are programmatically compiled from various online sources to illustrate current usage of the word 'unstable.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
Dictionary Entries Near unstable
Cite this Entry
“Unstable.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/unstable. Accessed 19 Apr. 2024.
Copy CitationKids Definition
unstable
adjective
un·sta·ble
ˌən-ˈstā-bəl
ˈən-
1
: not stable : not firm or fixed : fluctuating
unstable prices
an unstable tower
unstable weather
2
: readily changing in chemical composition or physical state or properties (as by breaking down into parts)
an unstable atomic nucleus
Medical Definition
unstable
adjective
un·sta·ble
-ˈstā-bəl
: not stable: as
a
: characterized by frequent or unpredictable changes
a patient in unstable condition
b
: readily changing (as by decomposing) in chemical composition or biological activity
unstable compounds
c
: characterized by lack of emotional control or stability
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