Muin is the Irish name of the eleventh letter of the Ogham alphabet, ᚋ.
The bríatharogaim kennings reflect the fact the Old Irish muin has three homonyms meaning "neck, upper part of the back", "wile, ruse, trick", and "love, esteem". Which of these gave the letter its name is not know for certain, but is thought to be "neck". This is related to the archaic Welsh mwn ("neck") and Latin monile. Its phonetic value is [m].