Meaning

• A dark image projected onto a surface where light (or other radiation) is blocked by the shade of an object.

  "My shadow lengthened as the sun began to set."

• Relative darkness, especially as caused by the interruption of light; gloom, obscurity.

  "I immediately jumped into shadow as I saw them approach."

• A area protected by an obstacle (likened to an object blocking out sunlight).

  "The mountains block the passage of rain-producing weather systems and cast a "shadow" of dryness behind them."

• A reflected image, as in a mirror or in water.

• That which looms as though a shadow.

  "I don't have a shadow of doubt in my mind that my plan will succeed. The shadow of fear of my being outed always affects how I live my life. I lived in her shadow my whole life."

• A small degree; a shade.

  "He did not give even a shadow of respect to the professor."

• An imperfect and faint representation.

  "He came back from war the shadow of a man."

• (police) A trainee, assigned to work with an experienced officer.

• One who secretly or furtively follows another.

  "The constable was promoted to working as a shadow for the Royals."

• An inseparable companion.

• A drop shadow effect applied to lettering in word processors etc.

• An influence, especially a pervasive or a negative one.

• A spirit; a ghost; a shade.

• (Latinism) An uninvited guest accompanying one who was invited.

• In Jungian psychology, an unconscious aspect of the personality.

Meaning

• To shade, cloud or darken.

  "The artist chose to shadow this corner of the painting."

• To block light or radio transmission from.

  "Looks like that cloud's going to shadow us."

• To secretly or discreetly track or follow another, to keep under surveillance.

• To represent faintly and imperfectly.

• To hide; to conceal.

• To accompany (a professional) during the working day, so as to learn about an occupation one intends to take up.

• To make (an identifier, usually a variable) inaccessible by declaring another of the same name within the scope of the first.

• To apply the shadowing process to (the contents of ROM).

Meaning

• Unofficial, informal, unauthorized, but acting as though it were.

  "The human resources department has a shadow information technology group without headquarters knowledge."

• Having power or influence, but not widely known or recognized.

  "The director has been giving shadow leadership to the other group's project to ensure its success."

• Acting in a leadership role before being formally recognized.

  "The insurgents’ shadow government is being crippled by the federal military strikes."

• Part of, or related to, the opposition in government.