OGAM
- an ancient alphabet, also OGHAM [n -S]
- ogham (an Old Irish alphabet) [n OGAMS]
- any of the 20 characters of this script, each consisting of one or more strokes for consonants and of notches for vowels cut across or upon a central line on a stone or piece of wood
- inscription employing this script
- alphabetical script used originally for inscriptions in an archaic form of Irish, from about the 5th to the 10th centuries