spyspyspiesspiedspying2verb (spies, spying, spied/, has spied)to watch a country, person or company and try to learn their secrets: He spied for his government for more than ten years.spy on somebody or somethingto watch somebody or something secretly: Have you been spying on me?spyspyspies1noun (pluralspies)a person who tries to learn secrets about another country, person or company