precarious vs unstable

precarious and unstable both are adjectives.

Word	Noun	Adjective	Verb	Adverb
precarious	No	Yes	No	No
unstable	No	Yes	No	No

As adjectives, precarious and unstable are synonyms defined as:

precarious (adjective)	unstable (adjective)
fraught with danger	lacking stability or fixity or firmness
not secure; beset with difficulties	subject to change; variable
affording no ease or reassurance	suffering from severe mental illness
	disposed to psychological variability
	highly or violently reactive
	affording no ease or reassurance