Volatile

1. noun

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

   “it was heated to evaporate the volatiles”

2. adjective

   marked by erratic changeableness in affections or attachments

   “fickle friends”

   Similar: fickle

3. adjective

   evaporating readily at normal temperatures and pressures

   “volatile oils”

4. adjective

   liable to lead to sudden change or violence

   “an explosive issue”

   Similar: explosive