Occurring by chance.
Entering or approaching, prior to reflection (more frequently incident).
Existing tangentially, being a byproduct, a tangent, or a likely consequence.
Loosely associated; of limited relevance except indirectly; only accidentally related.
Something that is incidental.
Minor items, not further defined. Incidental expense.
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.