Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
rāpīcĭus, a, um, adj. [rapum], of or belonging to rapes or turnips, rape-, turnip-: coles, Cato, R. R. 35, 2: semen, rape-seed, id. ib. 134, 1.
As subst.: rāpīcĭi, ōrum, m. (sc. caules), turnip-shoots, young turnipplants, Plin. 18, 13, 34, § 127.