| Welkin (n.) The visible regions of the air; the vault of heaven; the sky. Thesaurus Entries Caelus, aerosphere, air, atmosphere, azure, biosphere, blue sky, caelum, canopy, canopy of heaven, cerulean, cope, ecosphere, empyrean, ether, firmament, gaseous envelope, heaven, heavens, hyaline, lift, lifts, noosphere, sky, starry heaven, the blue, the blue serene, vault, vault of heaven |