In Irish mythology, Miach (Irish pronunciation: [mʲiːəx]) was a son of Dian Cecht of the Tuatha Dé Danann. He replaced the silver arm his father made for Nuada with an arm of flesh and blood; Dian Cecht killed him out of jealousy for being able to do so when he himself could not. Dian Cecht killed him by chopping Miach's head four times with his sword. The first strike only cut Miach's skin and Miach healed it. The second blow broke Miach's skull but Miach also healed that. The third cut grazed Miach's brain yet Miach could even heal this. Dian Cecht's fourth attack cut his son's brain in half and finally killed Miach. This resulted in 365 herbs growing from his grave, which his sister Airmid arranged, but which their father scattered. In any case, however, Miach is later seen in the story continuing to heal the Tuatha Dé by his father's and sister's side, so apparently there were no hard feelings.
- The Story of Miach and His Sister (The tale of Miach, Airmed & Dian Cecht)