The Collaborative International Dictionary
Masticin
Masticin \Mas"ti*cin\, n. (Chem.) A white, amorphous, tenacious substance resembling caoutchouc, and obtained as an insoluble residue of mastic.
Wiktionary
masticin
n. (context organic compound English) A white amorphous substance resembling rubber, obtained as an insoluble residue of mastic.