Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
jĕcuscŭlum, i, n. dim. [jecur], a little liver, Cic. Div. 2, 14, 33; Plin. 11, 37, 76, § 196; or jocusculum, Plin. l. l., Jahn; Apic. 4, 2.