Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
The word iumentarius could not be parsed. Trying a normal dictionary lookup:
jūmentārĭus, a, um, adj. [jumentum], of or belonging to draught-cattle (postclass.): mola, worked by draught-cattle, Dig. 33, 7, 26, § 1: contubernium, App. M. 10, p. 222, 34.