This is the 7933rd most frequent French word.
spy
A person who secretly gathers information about others, especially for a government or organization.
In this sentence, 'espionner' (to spy) is used as a verb to describe the action of observing covertly.
Le véritable but du personnage était d'espionner les activités de l'organisation.
The true goal of the character was to spy on the organization's activities.
Here, 'espion' (spy) is employed as a noun referring to a person who collects confidential information.
Cette montre possède une caméra cachée, comme un gadget d'espion.
This watch has a hidden camera, like a spy's gadget.
In this usage, 'espion' (spy) is used metaphorically as a noun.