Accidental means unplanned or unintended. Incidental means minor, secondary, or happening alongside something else.

This idiom means calming conflict. Its image comes from an old belief that oil could smooth rough water at sea.

Factoid once meant an invented claim that looked true because it appeared in print. Later, many people began using it for a brief fact.

Morbid suggests unhealthy fascination or gloom. Macabre points to eerie, death related imagery, tone, or atmosphere.