infiltrator
US /ˈɪn.fɪl.treɪ.t̬ɚ/
UK /ˈɪn.fɪl.treɪ.t̬ɚ/
1.
agent infiltré
a person who secretly becomes part of a group in order to get information or to influence the way the group thinks or behaves:
:
•
The infiltrator was identified and killed.