The vasus are usually listed as 8 and are part of a larger complex that includes 11 Rudras, 12 Adityas and 2 other gods to make the 33 gods of the Indian Pantheon.
Seen as Personifications of agni (fire), energy

Cologne Sanskrit Dictionary under Vasu:
A simplified version called = {jina} Sil. (only L
the sun ; the moon ; fire
a rope , thong ; a tree