telltalePronunciation: /ˈtɛlteɪl/Translate telltale | into Spanish Definition of telltale adjective [attributive] revealing, indicating, or betraying something:the telltale bulge of a concealed weapon noun 1British a person, especially a child, who reports others' wrongdoings or reveals their secrets. 2a device or object that automatically gives a visual indication of the state or presence of something. telltale in other Oxford dictionaries Definition of telltale in the US English dictionary