Ogam, spelled Ogham in modern Irish, is an Old Irish alphabet, it was possibly a cryptographic alphabet like the runic ones, and it may have had its own sign language and musical notation. The Ogam letters have names like the letters in the Rune Poem, and the letters have meanings we can glean from three collections of kennings, or Briatharogam (literally word-letters): words paired portmanteau style to make new meanings. It’s like a mini version of the Rune Poem’s riddles: two words give the clue instead of a whole stanza. These people understood how to work with brevity.
It is popular for people to think that all letters in the Ogam alphabet were always named after trees, and though there is a substantial grove of at least eight of them in the Ogam alphabet, there’s other stuff in there too. Take a look at the kennings for the letter R, ᚏ: tindem rucci… More
