Definitions of watch:

• noun:   a purposeful surveillance to guard or observe
• noun:   a small portable timepiece
• noun:   a period of time (4 or 2 hours) during which some of a ship's crew are on duty
• noun:   the period during which someone (especially a guard) is on duty
• noun:   a devotional watch (especially on the eve of a religious festival)
• noun:   a person employed to watch for something to happen
• verb:   observe with attention

  Example: "They watched as the murderer was executed"

• verb:   observe or determine by looking

  Example: "Watch how the dog chases the cats away"

• verb:   look attentively

  Example: "Watch a basketball game"

• verb:   see or watch
• verb:   be vigilant, be on the lookout, be on one's guard, be careful

  Example: "Watch out for pickpockets!"

• verb:   follow with the eyes or the mind

  Example: "The world is watching Sarajevo"

• verb:   find out, learn, or determine with certainty, usually by making an inquiry or other effort