'sphere', realm. The 3 spheres of existence are:
"Which things are of the sensuous sphere (kāmāvacara)?
Whatever things exist within the interval bounded beneath by the Avīci-hell and above by the Paranimmitavasavatti-heaven (s. deva), having therein their sphere, and being therein included, to wit: the groups of existence, the elements, bases (s. khandha, dhātu, āyatana), corporeality, feeling, perception, mental formations and consciousness, all these things are of the sensuous sphere. -
But which things are of the fine material sphere (rūpāvacara)?
Whatever things exist within the interval bounded beneath by the Brahma-world and above by the Akanittha-world (s. deva), having therein their sphere, and being therein included ... and also consciousness and mental factors in one who has entered the (fine-material) absorptions, or who has been reborn in that sphere, or who already during his life-time is living in happiness (of the absorptions), all these things are of the fine-material sphere. -
Which things are of the immaterial sphere (arūpāvacara)?
Consciousness and mental factors arising within the interval bounded beneath by the beings reborn in the sphere of unbounded space and above by the beings reborn in the sphere of neither-perception-nor-non-perception (s. jhāna 5-8), and consciousness and mental factors in one who has entered the (immaterial absorptions), or who has been reborn in that sphere, or who already during his lifetime is living in happiness (of the immaterial absorptions), all these things are of the immaterial sphere."
(Cf. Dhs. 1280, 1282, 1284; Vibh. XVIII). (App.).