Basu (Bengali: বসু), also Bose, Boshu, Bosu, or Bosh, is a Bengali Kulin Kayastha surname originating from the Bengal region of the Indian subcontinent. The name stems from Vāsu (Sanskrit: वसु), a term for God Viṣṇu, meaning 'dwelling in all forms'.[1][2]
Basus belong to the Bengali Kayastha caste, its component elements being putative Kshatriyas and mostly Brahmins, according to André Wink.[3] Basus are considered as Kulin Kayasthas of Gautam gotra, along with Ghoshes, Mitras and Guhas.[4]