Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
* ferrĭcrĕpĭnus, a, um, adj. [ferrum + crepo], resounding with the clanking of irons or fetters; comically formed: apud fustitudinas ferricrepinas insulas, i. e. ergastula, Plaut. As. 1, 1, 18.