Word Study
alumina
CIDE DICTIONARY
alumina, n. [L. alumen, aluminis. See Alum.].
One of the earths, consisting of two parts of aluminium and three of oxygen, Al2O3 . [1913 Webster]
" It is the oxide of the metal aluminium, the base of aluminous salts, a constituent of a large part of the earthy siliceous minerals, as the feldspars, micas, scapolites, etc., and the characterizing ingredient of common clay, in which it exists as an impure silicate with water, resulting from the decomposition of other aluminous minerals. In its natural state, it is the mineral corundum." [1913 Webster]
OXFORD DICTIONARY
alumina, n. the compound aluminium oxide occurring naturally as corundum and emery.
Etymology
L alumen alum, after soda etc.
ROGET THESAURUS
alumina
Softness
N softness, pliableness, flexibility, pliancy, pliability, sequacity, malleability, ductility, tractility, extendibility, extensibility, plasticity, inelasticity, flaccidity, laxity, penetrability, clay, wax, butter, dough, pudding, alumina, argil, cushion, pillow, feather bed, down, padding, wadding, foam, mollification, softening, soft, tender, supple, pliant, pliable, flexible, flexile, lithe, lithesome, lissom, limber, plastic, ductile, tractile, tractable, malleable, extensile, sequacious, inelastic, aluminous, remollient, yielding, flabby, limp, flimsy, doughy, spongy, penetrable, foamy, cushiony, flaccid, flocculent, downy, edematous, oedematous, medullary, argillaceous, mellow, soft as butter, soft as down, soft as silk, yielding as wax, tender as chicken.For further exploring for "alumina" in Webster Dictionary Online