| snoop(noun, verb, person, plant, examine) |
| detective(noun, information, plant, watch, investigate) |
| gumshoe(noun, slang, investigate, agent) |
| dick(noun, slang, investigate, agent) |
| private eye(noun, expression, agent, informer) |
| eye(noun, informal, investigate, agent) |
| shamus(noun, agent, informer, reporter) |
| eavesdropper(noun, information, agent, scout) |
| private investigator(noun, expression, agent, informer) |
| scout(noun, verb, person, plant, examine) |
| tail(noun, verb, examine, case, discover) |
| agent(noun, plant, operative, informer) |
| bloodhound(noun, agent, informer, reporter) |
| cop(noun, agent, informer, reporter) |
| fed(agent, informer, reporter, gumshoe) |
| informer(noun, information, plant, agent) |
| snooper(noun, agent, hound, sneak) |
| shadow(noun, verb, examine, case, discover) |
| spotter(noun, plant, watch, guard, agent) |
| Sherlock Holmes(expression, agent, informer, gumshoe) |