cablegram

[key-buh l-gram] /ˈkeɪ bəlˌgræm/
noun
1.
a telegram sent by underwater cable.
Origin
1865-70, Americanism; cable + (tele)gram
British Dictionary definitions for cablegram

cablegram

/ˈkeɪbəlˌɡræm/
noun
1.
a more formal name for cable (sense 5)