telltale

American  

[tel-teyl] / ˈtɛlˌteɪl /

noun

1. a person who heedlessly or maliciously reveals private or confidential matters; tattler; talebearer.

2. a thing serving to reveal or disclose something.

3. any of various indicating or registering devices, as a time clock.

4. Music. a gauge on an organ for indicating the air pressure.

5. an indicator showing the position of a ship's rudder.

6. a row of strips hung over a track to warn train crew members on freight trains that a low bridge, tunnel, or the like is approaching.

7. Yachting. (on a sailboat) a feather, string, or similar device, often attached to the port and starboard shrouds and to the backstay, to indicate the relative direction of the wind.

8. Squash. a narrow piece of metal across the front wall of a court, parallel to and extending 17 inches (43.2 centimeters) above the base: a ball striking this is an out.

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adjective

1. that reveals or betrays what is not intended to be known.

   a telltale blush.

2. giving notice or warning of something, as a mechanical device.

telltale British  

/ ˈtɛlˌteɪl /

noun

1. a person who tells tales about others

2. 1. an outward indication of something concealed

   2. ( as modifier )

      a telltale paw mark

3. any of various indicators or recording devices used to monitor a process, machine, etc

4. nautical

   1. another word for dogvane

   2. one of a pair of light vanes mounted on the main shrouds of a sailing boat to indicate the apparent direction of the wind

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Other Word Forms

• telltalely
  adverb

Etymology

Origin of telltale

First recorded in 1540–50; tell ¹ + tale

Explanation

Something that's telltale accidentally relays important information. A wise parent can tell who ate the last of the birthday cake by the telltale chocolate smudges on the culprit's face. The telltale dark circles under your teacher's eyes betray how little sleep he got last night, and a telltale bulge in a shopper's pocket is sometimes enough for a store owner to suspect she's a shoplifter. If it's telltale, its very presence reveals something. A famous occurrence of telltale, although it's spelled with a hyphen, is Edgar Allen Poe's story "The Tell-Tale Heart," about a murderer who imagines he's betrayed by the telltale beating of his victim's heart.

Example Sentences

Nevertheless, there was that telltale pricking at the eyes when your mind begins to think about what might have been.

From BBC • Apr. 26, 2026

A telltale sign, in many, was a request for money or an offer to rewrite his résumé for a fee.

From The Wall Street Journal • Apr. 16, 2026

Photos of the food on the menu are a telltale sign that it is geared toward tourists.

From Barron's • Mar. 8, 2026

Aside from the telltale rash, measles symptoms can include high fever, cough and red, watery eyes.

From Los Angeles Times • Feb. 7, 2026

Sanjeev noted that the symphony, now in its third movement, had reached a crescendo, for it pulsed with the telltale clashing of cymbals.

From "Interpreter of Maladies" by Jhumpa Lahiri