catu-vokāra-bhava: 'four-group existence', is the existence in the immaterial world (arūpa-loka; s. loka), since only the four mental groups (feeling, perception, mental formations, consciousness, s. khandha) are found there, the corporeality group being absent. Cf. pañca-vokāra-bhava, eka-vokāra-bhava. (App.: vokāra).

Buddhist Dictionary, Manual of Buddhist Terms and Doctrines, by NYANATILOKA MAHATHERA