We don't have synonyms for gurges yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are gurge, urges and purges.
(n) :
(heraldry) A series of typically four to six concentric annulets (in early heraldry, from at least the 1200s), or a spiralling line from the centre to the edge of the shield (in late heraldry); a stylized whirlpool.
(n) :
(heraldry) A series of typically four to six concentric annulets (in early heraldry, from at least the 1200s), or a spiralling line from the centre to the edge of the shield (in late heraldry); a stylized whirlpool.