What is "bardaisan"

Bardaisan (, Bardaiṣān), also known in Arabic as ابن ديصان (Ibn Daisan), also Latinized as Bardesanes, was a Syriac or Parthian gnostic and founder of the Bardaisanites. A scientist, scholar, astrologer, philosopher and poet, Bardaisan was also renowned for his knowledge of India, on which he wrote a book, now lost.