Name stories · Häagen-Dazs · 1960
A Bronx ice cream with a made-up Danish name sued a copycat, and lost
Reuben and Rose Mattus made ice cream in the Bronx and wanted a name that would stand out. They invented Häagen-Dazs to sound Danish; it means nothing in any language, and Danish doesn't even use the umlaut. In 1980 they sued Frusen Glädjé, another American ice cream with a Scandinavian-sounding name, and lost.
“There is no trademark, nor could there be”
US District Court, Southern District of New York, 1980
You can own an invented name, but not a borrowed accent.