1. the activity of secretly watching people or obtaining information about enemies or competitors

1. present participle of spy: secretly watching someone or something

Examples

• The government accused him of spying for a foreign country.
• She was caught spying on her neighbors through the window.
• Industrial spying has become a serious concern for many companies.
• The children were spying on their older sister’s phone conversation.
• He spent years spying behind enemy lines during the war.
• The detective was spying on the suspect from across the street.
• Corporate spying involves stealing trade secrets from competitors.