Pīti: rapture, enthusiasm rendered also by joy, happiness; interest it is one of the mental properties or properties cetasika and belongs to the group of mental constructions sankhāra-khandha As, in sutta texts, it is often linked in a compound word. with 'gladness' pāmojja or 'happiness' sukha some Western translations have wrongly taken it as a synonym of these two terms. Pīti, however, is not a feeling or a sensation, and hence does not belong to the feeling-group vedanā-khandha, but may be described psychologically as 'joyful interest'. As such it may be associated with advantageous as well as with disadvantageous and neutral states of consciousness.
A high degree of rapture is characteristic of certain stages in meditative concentration, in insight practice vipassanā as well as in the first two absorptions jhāna. In the latter it appears as one of the factors of absorption jhānanga see: jhāna and is strongest in the 2nd absorption. Five degrees of intensity in meditative rapture are described in Vis.M IV. 94ff. It is one of the factors of enlightenment bojjhanga.
Maha Thera Nyanatiloka. Manual of Buddhist Terms and Doctrines, Buddhist Publication Society, first edition 1952.