One who tattles on others; an informer or talebearer. (noun)
Revealing; telltale. (adjective)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "tattletale" in a sentence
"The penalty for such a violation was for the immediate surrender of the paper, which was soon retrieved by the stealth "tattletale" who was hovering on the periphery as his rival was subjected to disciplinary action."
"The "tattletale" lights will make it easier for troopers to enforce traffic laws for failing to stop at red lights and failing to yield the right of way, he said."
"The new "tattletale" lights were installed last week on Highway 12 at the intersections of Highway 124 and Humorist Road in Burbank."