Source : Webster's Revised Unabridged Dictionary (1913)

Cablegram \Ca"ble*gram`\ (k[=a]"b'l*gr[a^]m`), n. [Cable, n. +
   Gr. gra`mma a writing, a letter.]
   A message sent by a submarine telegraphic cable.

   Note: [A recent hybrid, sometimes found in the newspapers.]

Source : WordNet®

cablegram
     n : a telegram sent abroad [syn: {cable}, {overseas telegram}]