Where does “eachtrán” come from?

eachtrán (Irish) comes from Irish án, from Old Irish ín, from Proto-Celtic sindos, from Proto-Indo-European sḗm, from Proto-Indo-European sem- — together, one.

eachtrán (Irish): alien

Definitions

alien

Ancestry of “eachtrán”, step by step

eachtrán traces back through two separate lines of ancestry.

via Irish án

Step	Language	Word	Meaning
1	Irish	án	bright, brilliant; splendid, noble
2	Old Irish	ín	fast, period of fasting
3	Proto-Celtic	sindos	this
4	Proto-Indo-European	sḗm	one
5	Proto-Indo-European	sem-	together, one

via Old Irish echtar

Step	Language	Word	Meaning
1	Old Irish	echtar	without, outside
2	Proto-Celtic	*exteros	outside
3	Proto-Indo-European	h₁eǵʰs	out

Every word from Proto-Indo-European sem- →Every word from Proto-Indo-European sḗm →Every word from Proto-Celtic sindos →