Vasi

Vasī: 'mastery'. Vis.M IV speaks of 5 kinds of m., which anyone who wishes to develop the absorption Jhanas should acquire first of all, with regard to the 1st absorption, namely: mastery in adverting to it āvajjana-vasī in entering it samāpajjana-vasī in determining it adhitthāna-vasī in rising therefrom vutthāna-vasī in retrospection paccavekkhana-vasī.

References

Maha Thera Nyanatiloka. Manual of Buddhist Terms and Doctrines, Buddhist Publication Society, first edition 1952.