ROCAMBOLE
Roc"am*bole, n. Etym: [F.] [Written also rokambole.] (Bot.)
Defn: A name of Allium Scorodoprasum and A. Ascalonium, two kinds of garlic, the latter of which is also called shallot.
ROCCELLIC
Roc*cel"lic, a. Etym: [F. roccellique, fr. roccelle archil, It. & NL.
roccella, fr. It. rocca a rock, because archil grows on rock.]
(Chem.)
Defn: Pertaining to, or designating, a dibasic acid of the oxalic series found in archil (Roccella tinctoria, etc.), and other lichens, and extracted as a white crystalline substance C17H32O4.
ROCCELLIN
Roc*cel"lin, n.
Defn: A red dyestuff, used as a substitute for cochineal, archil, etc. It consists of the sodium salt of a complex azo derivative of naphtol.
ROCHE
Roche, n. Etym: [See Rock.]
Defn: Rock. [Obs.] Chaucer.
ROCHE ALUM
Roche" al`um. (Chem.)
Defn: A kind of alum occuring in small fragments; — so called from Rocca, in Syria, whence alum is said to have been obtained; — also called rock alum.