og·ham or og·am (ŏgəm, ōəm)
a. An alphabetic system of inscribed notches for vowels and lines for consonants used to write Old Irish, chiefly on the edges of memorial stones, from the fifth to the early seventh century.
b. A character used in this alphabet.
a. An inscription in the ogham alphabet.
b. A stone inscribed in the ogham alphabet.
[Irish Gaelic, from Old Irish ogom, after Ogma, name of a Celtic god; see ag- in the Appendix of Indo-European roots.]
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Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.