D defs.my
Entry 1 sense Webster, 1913

fibroin

/(fī"brō̇*ĭn [or] fĭb"rō̇*ĭn)/ · fi·bro·in · IPA
01 n. A variety of gelatin; the chief ingredient of raw silk, extracted as a white amorphous mass.
  1. 1.
    A variety of gelatin; the chief ingredient of raw silk, extracted as a white amorphous mass.(Chem.)