/troh pee"euh lin/ , n. Chem.
any of a number of orange or yellow azo dyes of complex molecular structure.
Also, tropeolin .
[ 1875-80; Tropaeol ( um ) nasturtium, genus of plants yielding the dyes (equiv. to L tropae ( um ) TROPHY + -olum, neut. of -olus -OLE 1 ) + -IN 2 ]