S: (n) matter (that which has mass and occupies space) "physicists study both the nature of matter and the forces which govern it"
S: (n) part, portion, component part, component, constituent (something determined in relation to something that includes it) "he wanted to feel a part of something bigger than himself"; "I read a portion of the manuscript"; "the smaller component is hard to reach"; "the animal constituent of plankton"
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) changeable, changeful (such that alteration is possible; having a marked tendency to change) "changeable behavior"; "changeable moods"; "changeable prices"