It is commonly called alumina, and may also be called aloxide, aloxite, or alundum depending on particular forms or applications. It commonly occurs in its crystalline polymorphic phase Î±-Al 2 O 3, in which it composes the mineral corundum, varieties of which form the precious gemstones ruby and sapphire.
rain cloud. (meteorology). Any cloud from which rain falls; a popular term having no technical denotation. 1  Facebook. 2  Twitter.
Meaning: A heavy rain. Classified under: Nouns denoting natural phenomena. Synonyms: torrent; soaker; pelter; downpour; cloudburst; deluge; waterspout. Hypernyms (torrent is a kind of...): rain; rainfall (water falling in drops from vapor condensed in the atmosphere)