The Collaborative International Dictionary
Telegraph \Tel"e*graph\, v. t. [imp. & p. p. Telegraphed; p. pr. & vb. n. Telegraphing.] [F. t['e]l['e]graphier.] To convey or announce by telegraph.
Wiktionary
n. A communication by telegraph. vb. (present participle of telegraph English)
Wikipedia
In sporting terminology, to telegraph is to unintentionally alert an opponent to one's immediate situation or intentions. The sporting use of the term telegraph draws a direct comparison with the communication device of the same name. "Telegraphing" always refers to a reflexive physical action rather than a protracted or intellectual give-away. For example, a boxer rotating his shoulders to throw a hook would be telegraphing. A rugby team betraying its line-out plays by using an easily decoded line-out code is not telegraphing.
While telegraphing is a hazard for any sporting event, it is particularly risky at upper levels of competition where talented players are better able to anticipate and react to telegraphed actions. The ability to suppress telegraphing is often the hallmark of elite athletes.
Usage examples of "telegraphing".
At Constantinople every body fell to telegraphing the American Consuls at Alexandria and Beirout to give notice that we wanted dragomen and transportation.
When a man invents a new style of horse-collar or discovers a new and superior method of telegraphing, our government issues a patent to him that is worth a fortune.
Therefore, when the clerk had finished telegraphing the last lines dictated by Blount, Alcide Jolivet noiselessly took his place at the wicket, and, just as his rival had done, after quietly depositing a respectable pile of roubles on the shelf, he delivered his dispatch, which the clerk read aloud: "Madeleine Jolivet, 10, Faubourg Montmartre, Paris.