Overly repetitive and unchallenging.
Having no sensible meaning or purpose.
Heedless.
Lacking a mind.
Showing a lack of forethought or sense.
Unpredictable, erratic or fickle; mercurial.
The metal mercury.
An amalgam of mercury and tin applied to the backs of mirrors, quicksilvering.
To overlay with quicksilver.
To treat with quicksilver.