Definition of "Volatile" :

noun: a volatile substance; a substance that changes readily from solid or liquid to a vapor

"It was heated to evaporate the volatiles."

adjective: tending to vary often or widely

"Volatile stocks."

adjective: marked by erratic changeableness in affections or attachments

"A flirt's volatile affections."

adjective: liable to lead to sudden change or violence

"A volatile situation with troops and rioters eager for a confrontation."

adjective: evaporating readily at normal temperatures and pressures

"Volatile oils."