Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
aescŭlĕus (not esc-), a, um, adj. [aesculus], of the Italian oak, and poet., in gen., of oak: aesculeae capiebat frondis honorem, i. e. an oaken garland, Ov. M. 1, 449; so Pall. 1, 9.