AHOY (AHOJ)

Miriam Webster:

Main Entry: hoy
Pronunciation: 'hoi
Function: interjection
Etymology: Middle English
Date: 14th century
-- used in attracting attention or in driving animals

Alexander Graham Bell suggested Ahoy as a greeting for his new invention, the telephone. (It didn't stick. The last remaining person to use it is Monty Burns, on The Simpsons.)

Plus ~10 million Czechs