volatile
vol-a-tile
adjective
(Of a substance) easily evaporates at normal temperatures and pressures.
"Petrol is a highly volatile liquid."
adjective
Likely to change rapidly and unpredictably, often for the worse.
"The stock market is very volatile."
Thesaurus
Synonyms: changeable, changeful, explosive, unstable, evaporable, vaporific, vapourisable, vaporizable, volatilizable, volatilisable, vapourific, inconstant
Antonyms: nonvolatile, nonvolatilisable, nonvolatilizable