S: (adj) volatile (evaporating readily at normal temperatures and pressures) "volatile oils"; "volatile solvents"
S: (adj) explosive, volatile (liable to lead to sudden change or violence) "an explosive issue"; "a volatile situation with troops and rioters eager for a confrontation"
S: (adj) unstable (lacking stability or fixity or firmness) "unstable political conditions"; "the tower proved to be unstable in the high wind"; "an unstable world economy"
W: (adj) stable [Opposed to: unstable] (resistant to change of position or condition) "a stable ladder"; "a stable peace"; "a stable relationship"; "stable prices"