ogham

Where does the word "ogham" come from? It comes from Old Irish ogam, and was adopted directly into English (1620s).

Ogham’s story begins in Old Irish: ogam meant “ogham script.” An alphabet of notches cut along the edge of a stone; around 400 inscriptions survive, most in southern Ireland, and medieval tradition credited its invention to the god Ogma. It reached English by 1620s as ogham. Scholars could read the stones thanks to a key preserved in the Book of Ballymote, a manuscript of about 1390. Today, ogham means an ancient Irish alphabet of strokes along a line or stone edge.

1. Stage 1 · Old Irish · 400s ogam "ogham script", an alphabet of notches cut along the edge of a stone; around 400 inscriptions survive, most in southern Ireland, and medieval tradition credited its invention to the god Ogma.
2. Stage 2 · English · 1620s ogham "early Irish alphabet", scholars could read the stones thanks to a key preserved in the Book of Ballymote, a manuscript of about 1390.