telegram (n.) Look up telegram at
"telegraphic dispatch," according to Bartlett's 1859 edition a coinage of E. Peshine Smith of Rochester, N.Y., from tele-, as in telegraph + -gram, and introduced in the Albany "Evening Journal" of April 6, 1852. Damned in the cradle by purists who pointed out that the correct formation would be telegrapheme (which is close to the Modern Greek word).
May I suggest to such as are not contented with 'Telegraphic Dispatch' the rightly constructed word 'telegrapheme'? I do not want it, but ... I protest against such a barbarism as 'telegram.' [Richard Shilleto, Cambridge Greek scholar, in the London "Times," Oct. 15, 1857]
Related: Telegrammic.