mercurial

changeable effervescent erratic impulsive resilient unpredictable volatile

blowing hot and cold bubbleheaded buoyant capricious elastic expansive fickle flaky flip fluctuating gaga gay inconstant irregular irrepressible lighthearted lively lubricious mad mobile movable quicksilver spirited sprightly ticklish unstable up-and-down variable yo-yo

certain constant predictable reliable stable steady sure unchanging

calm tranquil unchangeable unperturbable unvarying