/awr"seuh nawl', -nol'/ , n. Chem.
a white, crystalline, water-soluble solid, C 7 H 8 O 2 , sweet but unpleasant in taste, that reddens on exposure to air: obtained from many lichens or produced synthetically and used chiefly as a reagent for certain carbohydrates.
Also, orcin /awr"sin/ .
[ 1875-80; orcin ( a ) ( orcello ORCHIL, by alter.) + -OL 2 ]