"Long after individual matches and goals are forgotten, this will be remembered as the Vuvuzela World Cup," said Jurga Zilinskiene, managing director of London-based firm Today Translations.
"Vuvuzela" was chosen by 75% of more than 320 linguists from over 60 countries, who were asked to choose the word with the biggest impact on the tournament.
"Thanks to the World Cup, vuvuzela has the entered the shared language of the world and joined the ranks of words that need no translation," said Zilinskiene.
The tuneless plastic horn blown by fans was a top World Cup newsmaker and has been snapped up abroad. Experts have warned it can damage hearing.
The much-debated official Jabulani ball, mascot Zakumi and the Bafana Bafana national South African team each won 4% of the votes.