经久未曾听闻
[jīng jiŭ wèi céng tīng wén]
'经久未曾听闻' can be translated as 'Long Unheard Of'. The name indicates rarity or something or someone who has not been around for so long they are considered scarce. Perhaps even mythical in status because no news or mention of them was known after such long absence from the common scene.