Nia Segamain, son of Adamair, was, according to medieval Irish legend and historical tradition, a High King of Ireland.
Geoffrey Keating says his mother was the presumed woodland goddess Flidais of the Tuatha Dé Danann, whose magic made wild does give milk as freely as domesticated cattle during his reign.
The Lebor Gabála synchronises his reign with that of Ptolemy VIII Physcon in Egypt (145–116 BC).
[3] His name means "sister's son or champion of Segamon",[4] and is perhaps related to Segomo, an ancient Gaulish deity equated in Roman times with Mars and Hercules.
[5] A slightly more historical Nia Segamain occurs in early Eóganachta pedigrees, and this is sometimes interpreted as evidence for the Gaulish origins of the dynasties.