Two entries with the name Anoeth.
Anoeth
A knight slain by Tristan during a tournament in Ireland.
Anoeth
A British city in which Arthur was imprisoned by Gwen Pendragon for three days, according to a Triad.
Source
The Stanzas of the Graves | 10th century or 11th century
Triads of the Island of Britain | 11th century to 14th century
Meaning
The word anoeth is an intensifier comparable to the English “incredible”, possibly meaning either “wonderful” or “difficult”. The word is used to describe Arthur’s grave in a Welsh poem, which may indicate an early Welsh belief in the mysterious circumstances surrounding Arthur’s death.