Etymology 1 (basi)
From English bus.
basi (ma class, plural mabasi)
Etymology 2 (basi) Conjunction
1) well; then; so
Imbe basi! Well, sing!
Generally placed after a verb to support an order or express resignation.
From Wiktionary: https://en.wiktionary.org/wiki/basi
On usage notes: Also used when telling a story/in conversation to introduce a new paragraph: Alright, so then...