telltale

[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 cm) above the base: a ball striking this is an out.
adjective
9.
that reveals or betrays what is not intended to be known:
a telltale blush.
10.
giving notice or warning of something, as a mechanical device.
Origin
1540-50; tell1 + tale
Related forms
telltalely, adverb
Examples from the web for telltale
  • They also tested three phony blue diamonds-of which none had the telltale red signature.
  • He sees the telltale triangle in the mud, raises his dart's point, and drives it down with all he has in him.
  • He also listens for a telltale hollow report, which would mean the creature within is dead and shriveled.
  • New research shows that there are many testable, telltale biomarkers.
  • Exhumations to obtain telltale genetic fingerprints now seem to take place every other week.
  • Only her blood sample, which contained the disease's telltale antibodies, revealed that she was sick.
  • Because a few growing seasons will cover the tracks of shallow slides, their telltale scars are harder to spot.
  • She blows on the damp spot until it is completely dry, so the pen will not leave a telltale smudge.
  • They sat down at last beneath the pine trees to eat their lunch, letting fall the telltale eggshells.
  • Unfortunately, stuck into one as a bookmark was a telltale sprig of raffia twine.
British Dictionary definitions for telltale

telltale

/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
Word Origin and History for telltale

1540s (n.), 1590s (adj.), from tell + tale, in phrase to tell a tale "relate a false or exaggerated story" (late 13c.).