|1.||a person who tells tales about others|
|2.||a. an outward indication of something concealed|
|b. (as modifier): a telltale paw mark|
|3.||any of various indicators or recording devices used to monitor a process, machine, etc|
|a. another word for dogvane|
|b. one of a pair of light vanes mounted on the main shrouds of a sailing boat to indicate the apparent direction of the wind|
Divulge secrets, as in Don't trust him; he's apt to tell tales. This expression was first recorded about 1350. A variant, tell tales out of school, first recorded in 1530, presumably alluded to schoolchildren gossiping but was soon broadened to revealing secret or private information. Both may be obsolescent.