noun, verb ·Uncommon ·Advanced level
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"Venice also needed alum for trade, since it was the point of departure for overland transportation of alum to southern Germany and its cloth-manufacturing Free Cities."
"1961 Spring, Anchora of Delta Gamma, Volume LXXVII, No. 3, page 59, Evanston-North Shore alums are happy to open their homes to Sigma actives for special social events."
"With weld and cochineal, which are colouring matters the most sensible to the action of sulphate of iron, the purified alums gave us colours more brilliant, fresh, and in a slight degree lighter; while those with our common alums were all duller, and evidently of a deeper hue."
"The silk should be boiled at the rate of 20 parts of soap per cent. , and then alumed. The aluming need not be so strong as for the fine crimson"
"An astringent, like an alum block or styptic pencil, helps close and heal small cuts after shaving."
An astringent salt, usually occurring in the form of pale crystals, much used in the dyeing and tanning trade and in certain medicines, and now understood to be a double sulphate of potassium and aluminium (K₂SO₄·Al₂(SO₄)₃·24H₂O).
Common synonyms include: potash alum, aluminum potassium sulfate, aluminum sulfate, alumna, alumnus, ammonia alum.
An astringent, like an alum block or styptic pencil, helps close and heal small cuts after shaving.
Pronounced /ˈæl.əm/.
From Middle English alum, alum, alym, alyme, from Anglo-Norman alum, alun, from Latin alūmen.
Clipping of alumnus and alumna (> alumn- > alum), by the removal of the originally Latin gender-specific nominative singular case endings -us (masculine) and -a (feminine).