Where does “Lielbritānija” come from?

Lielbritānija (Latvian) comes from Latvian liels, from Proto-Indo-European lei-, from Proto-Indo-European ēl- — awl, prong.

Ancestry of “Lielbritānija”, step by step

Step	Language	Word	Meaning
1	Latvian	liels	big, large; intense, loud; high, great, large
2	Proto-Indo-European	lei-	to flow, pour; to bend; to pour, to flow, to drip
3	Proto-Indo-European	ēl-	awl, prong

Lielbritānija — Etymology, Origin & Word History | Etymology Explorer