Definition of: ogham

(og′əm) noun
1. An ancient British and Irish script of the fifth and sixth centuries having an alphabet of 20 characters (lines, dots, or notches) arranged along an arris, and ascribed to the god Ogma: found cut into the edges of tombstones and pillars.
2. An inscription in that script; also, any one of the characters used. Also og′am. [<Irish <OIrish ogam, after Ogma, its mythical inventor]
—o·gham·ic (ō·gam′ik) adjective