Definition of "observable"

In 1913, in the same year that Mother's Day became a nationally observable holiday, the American people passed another milestone: for the first time in American history more than one person in one thousand was divorced.

2004, John Lukacs, A New Republic: A History of the United States in the Twentieth Century

Although intellectual property rights, such as patents, are highly observable, they are mostly limited to product technologies. Process technologies, or the routines endemic in the firm's production, are not readily observable, and thus cannot be easily imitated.

2008, David J. Teece, Technological Know-how, Organizational Capabilities, and Strategic Management