Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
dūrĭuscŭlus, a, um, adj. dim. [durus, II. A.], somewhat hard, rough, or harsh (perh. only in the foll. passages).
Of expression: Catullus, Plin. H. N. praef. § 2; cf. versus, Plin. Ep. 1, 16, 5.