Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
‡ crĕpĭtŭlum (crĕpic-; i, n.) ornamentum capitis, idem enim in capitis motu crepitum facit, Paul. ex Fest. p. 52, 19 Müll. Form crĕpĭdŭlum, Tert. Pall. 4.