Where does “mac-bràthar” come from?

mac-bràthar (Scottish Gaelic) comes from Scottish Gaelic mac, from Middle Irish mac, from Old Irish macc, from Primitive Irish ᚋᚐᚊᚊᚔ, from Proto-Celtic makkʷos, from Proto-Indo-European meh₂ḱ- — to raise, increase; long.

mac-bràthar (Scottish Gaelic): fraternal nephew

Definitions

fraternal nephew

Ancestry of “mac-bràthar”, step by step

mac-bràthar traces back through two separate lines of ancestry.

via Scottish Gaelic mac

Step	Language	Word	Meaning
1	Scottish Gaelic	mac	son; Commonly used as a prefix of Irish and...
2	Middle Irish	mac	son
3	Old Irish	macc	son; child
4	Primitive Irish	ᚋᚐᚊᚊᚔ	Alternative form of ᚋᚐᚊᚔ
5	Proto-Celtic	makkʷos	—
6	Proto-Indo-European	meh₂ḱ-	to raise, increase; long

via Scottish Gaelic bràthair

Step	Language	Word	Meaning
1	Scottish Gaelic	bràthair	brother, male sibling
2	Old Irish	bráthair	brother, cousin, kinsman
3	Proto-Celtic	brātīr	brother
4	Proto-Indo-European	bʰréh₂tēr	brother

Every word from Proto-Indo-European meh₂ḱ- →Every word from Proto-Celtic makkʷos →Every word from Primitive Irish ᚋᚐᚊᚊᚔ →