The name 'Arthur' can mean 'bear' (derived from Celtic Artos) or 'stone' (derived from Celtic Art.)
In Irish it's "fiáin"
The surname Mahone is a variation of Mahon, of Celtic or Gaelic origin and means bear.
There's actually no such language as "Celtic". Celtic refers to a group of dozens of languages, six of which are spoken today:BretonCornishIrish GaelicManxScottish GaelicWelsh
In Irish it's feall / brath
Bear! ;D
Some words that can be made with the letters in 'bear' are:aarebarbarebeeareraReba
I don't know if 'Green man' actually is used in Celtic languages. The wikipedia article mentions an ancient Celtic god called Viridios which may derive from 'green'.
'without an end' or 'by ourselves'
In Irish it's lúbra / cathair gríobhháin
The Celtic language family is divided into a "Goidelic" (Irish, Scots and Manx Gaelic) as well as a "Brythonic" branch (Welsh, Breton, Cornish). In other words, Gaelic is a part of the larger Celtic universe.
Square Bear