One entry found for
unstable.
Main Entry:
un·sta·ble 
Pronunciation:

n-
st
-b
l, 
n-
Function:
adjective
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>