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orcein

American  
[awr-see-in] / ˈɔr si ɪn /

noun

Chemistry.
  1. a red dye, the principal coloring matter of cudbear and orchil, obtained by oxidizing an ammoniacal solution of orcinol.


orcein British  
/ ˈɔːsɪɪn /

noun

  1. a brown crystalline material formed by the action of ammonia on orcinol and present in orchil: used as a dye, biological stain, and antiseptic. Formula: C 28 H 24 O 7 N 2

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of orcein

1830–40; arbitrary alteration of orcin; orcinol