Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
ŏpĭtŭlātor (ŏpĭtŭlus), ōris, m. [opitulor], a helper, aider, succorer (post-class.): opitulus Juppiter, et opitulator dictus est, quasi opis lator, Paul. ex Fest. p. 184 Müll.: sodalis opitulator, App. Flor. 3, p. 353, 25; Hier. in Isa. 7, 17, § 10.