From Wiktionary, the free dictionary
Likely from English Baso.
bsa
- (international standards) ISO 639-3 language code for Abinomn.
bsa
- to feed
- Singh, U Nissor (1906) Khasi-English dictionary[1], Shillong: Eastern Bengal and Assam Secretariat Press, page 15. Searchable online at SEAlang.net.