Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
praesumptĭōsus (-tŭōsus), a, um, adj. [praesumptio], full of boldness, presumptuous (post-class.): juvenis (al. praesumptuosum), Sid. Ep. 1, 11.
Transf.: vestigia, Sid. Ep. 1, 1.