Where does “Breatainn Bheag” come from?

Breatainn Bheag (Scottish Gaelic) comes from Scottish Gaelic beag, from Old Irish bec, from Proto-Celtic *biggos.

Ancestry of “Breatainn Bheag”, step by step

Step	Language	Word	Meaning
1	Scottish Gaelic	beag	small, little, short, diminutive; disagreeable;...
2	Old Irish	bec	small
3	Proto-Celtic	*biggos	—

Breatainn Bheag — Etymology, Origin & Word History | Etymology Explorer