You searched for: “surveillants
surveillant (s) (noun), surveillants (pl)
1. A close observation; especially, of a suspected spy or transgressor: Although he was not aware of it, the criminal investigators had a surveillant on the man because there was an indication that he might be up to some kind of dangerous activity.
2. Etymology: from Latin sur, "over" + veiller, "watch" or vigilare, "to keep watch".