Where does “scréachóg” come from?

scréachóg (Irish) comes from Irish óg, from Old Irish óc, from Proto-Celtic *yuwankos, from Proto-Indo-European h₂yuh₁n̥ḱós, from Proto-Indo-European h₂yuh₁en-, from Proto-Indo-European h₂ey- — vital force, life, age, eternity; day, morning.

scréachóg (Irish): jay

Definitions

Ancestry of “scréachóg”, step by step

scréachóg traces back through two separate lines of ancestry.

via Irish óg

Step	Language	Word	Meaning
1	Irish	óg	young; junior, minor; new, fresh, early
2	Old Irish	óc	young; young man; warrior
3	Proto-Celtic	*yuwankos	young
4	Proto-Indo-European	h₂yuh₁n̥ḱós	—
5	Proto-Indo-European	h₂yuh₁en-	young
6	Proto-Indo-European	h₂ey-	vital force, life, age, eternity; day, morning

via Irish scréach

Step	Language	Word	Meaning
1	Irish	scréach	screech, scream, shriek; screech, shriek
2	Old Irish	scréch	cry, shout, scream

Every word from Proto-Indo-European h₂ey- →Every word from Proto-Indo-European h₂yuh₁en- →Every word from Proto-Indo-European h₂yuh₁n̥ḱós →