Again, this is utter nonsense. Why do you not look up the etymology of this word? It is of ancient origin, and doesn't refer to the union of the countries of the British Isles. It was noted by the Greeks in ancient times. It is not a Hebrew word, but a P-Celtic word, perhaps meaning "tattooed" or "painted".
In Gaelic the name for the ancient Picts is "cruithne", which is the same word.
In writings from Ireland, the name Cruthin, Cruthini, Cruthni, Cruithni or Cruithini (Modern Irish: Cruithne) was used to refer both to the Picts and to another group of people who lived alongside the Ulaid in eastern Ulster. It is generally accepted that this is derived from *Qritani, which is the Goidelic/Q-Celtic version of the Britonnic/P-Celtic *Pritani. From this came Britanni, the Roman name for those now called the Britons. It has been suggested that Cruthin referred to all Britons not conquered by the Romans—those who lived outside Roman Britannia, north of Hadrian's Wall.
So this demonym is thousands of years older than the Union of England, Scotland and Ireland.