unstable

As adjectives the difference between sustainable and unstable

is that sustainable is able to be sustained while unstable is having a strong tendency to change.

As adjectives the difference between fluctuant and unstable

is that fluctuant is that fluctuates, or causes fluctuation while unstable is having a strong tendency to change.

As adjectives the difference between tangent and unstable

is that tangent is (geometry) touching a curve at a single point but not crossing it at that point while unstable is having a strong tendency to change.

As a noun tangent

is (geometry) a straight line touching a curve at a single point without crossing it there.

Rickety is a synonym of unstable.

As adjectives the difference between unstable and rickety

is that unstable is having a strong tendency to change while rickety is of an object: not strong or sturdy, as because of poor construction or upkeep; not safe or secure; giddy; shaky.

As an adjective unstable

is having a strong tendency to change.

As a noun unsteadiness is

the quality of being unsteady.

As a noun wobble

is an unsteady motion.

As a verb wobble

is to move with an uneven or rocking motion, or unsteadily to and fro.

As an adjective unstable is

having a strong tendency to change.

As a noun insecurity

is a lack of security, uncertainty.

As an adjective unstable is

having a strong tendency to change.

Unstable is a related term of veering.

As an adjective unstable

is having a strong tendency to change.

As a verb veering is

.

As a noun veering is

a motion that veers; a sudden swerve.

As adjectives the difference between unstable and changeful

is that unstable is having a strong tendency to change while changeful is changing frequently; very susceptible to change; variable; fickle.

As a verb shake

is to cause (something) to move rapidly in opposite directions alternatingly.

As a noun shake

is the act of shaking something.

As an adjective unstable is

having a strong tendency to change.