noun

• (obsolete or poetic) A reflected image, as in a mirror or in water.
  "Some there be that ſhadowes kiſſe, / Such haue but a ſhadowes bliſſe."
• (figurative) That which looms as though a shadow.
  "Yea, though I walk through the valley of the shadow of death, I will fear no evil: for thou art with me; thy rod and thy staff they comfort me."
• (chiefly in the negative) A small degree; a shade.
  "He did not give even a shadow of respect to the professor."
• (UK, law enforcement) A trainee, assigned to work with an experienced officer.

adj

• (Commonwealth, politics) Part of, or related to, the opposition in government.
• (US, politics) Acting in a leadership role before being formally recognized.
  "The shadow cabinet cannot agree on the terms of the agreement due immediately after they are sworn in."

verb

• (transitive) To shade, cloud, or darken.
  "The artist chose to shadow this corner of the painting."
• (transitive) To block light or radio transmission from.
  "Looks like that cloud's going to shadow us."
• (particularly espionage) To secretly or discreetly track or follow another, to keep under surveillance.
  "Soon after departure, we cross the invisible border into Scotland to enjoy more stunning coastal scenery, before the line finally swings inland at Burnmouth to traverse pine-clad valleys, shadowed by the A1 trunk road until we rejoin the coast at Cove, east of Dunbar."
• (transitive) To represent faintly and imperfectly.
  "Ah, ye admonitions and warnings! why stay ye not when ye come? But rather are ye predictions than warnings, ye shadows!"