Knight challenges Gawain to rise to the ideals of honour and religious practices. His name, the Green Knight, shows his opposition to nature: the colour green represents forces of nature, and the word "knight" connects him to society and civilisation. While the Green Knight represents the primitive, and uncivilised side of man's nature, he also opposes nature as well. The description of the Green Knight, which he shares with his green horse, shows the central idea of human nature's potential. The colour green Given the varied and even contradictory interpretations of the colour green, its precise meaning in the poem remains ambiguous. In English folklore and literature, green was traditionally used to symbolise nature and its associated attributes: fertility and rebirth. Stories of the medieval period also used it to allude to love and the base desires of man. Because of its connection with faeries and spirits in early English folklore, green also signified witchcraft, devilry and evil. It can also represent decay and toxicity. When combined with gold, as with the Green Knight and the girdle, green was often seen as representing youth's passing. In Celtic mythology, green was associated with misfortune and death, and therefore avoided in clothing. The green girdle, originally worn for protection, became a symbol of shame and cowardice; it is finally adopted as a symbol of honour by the knights of Camelot, signifying a transformation from good to evil and back again; this displays both the spoiling and regenerative connotations of the colour green. There is a possibility, as Alice Buchanan has argued, that the colour green is erroneously attributed to the Green Knight due to the poet's mistranslation or misunderstanding of the Irish word , which could either mean grey or green, or the identical word in Cornish. has been used to denote a range of colours: light blues, greys, and greens of the sea and grass. In the Death of Curoi (one of the Irish stories from Bricriu's Feast), Curoi stands in for Bertilak, and is often called "the man of the grey mantle" which corresponds to Welsh Brenin Llywd or Gwynn ap Nudd. Though the words usually used for grey in the Death of Curoi are or , roughly meaning milk-coloured and shadowy respectively, in later works featuring a green knight, the word is used and may have been the basis of misunderstanding. Girdle The girdle's symbolic meaning, in Sir Gawain