quicksilver
adjective
1. liable to sudden unpredictable change
- a quicksilver character, cool and willful at one moment, utterly fragile the next
Similar word(s): changeable, changeful, erratic, fickle, mercurial
noun
1. a heavy silvery toxic univalent and bivalent metallic element; the only metal that is liquid at ordinary temperatures
Similar word(s): hydrargyrum, mercury
verb
1. To overlay with quicksilver.
2. To treat with quicksilver.