Thats a remarkably similar word to what we use today in euskera : zorioneko. Euskera was a very free form language, mostly relying on spoken word, up until the 1980s when Euskaltzaindia introduced "Euskera batua". In a way, the euskera spoken in the early 20th century should be really similar to whatever version of it they were speaking 2000 years ago, it's really impressive

Should be highlighted the previous "oldest writings in basque" we had (Glosas Emilianses) dated from either the 10th or 11th centuries. These scribes also included the first few Castilian Spanish writings so this new discovery is really remarkable and highlights the isolated nature of early Basque settlers