Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
immŏlātor (inm-), ōris, m. [immolo], one who offers a sacrifice, a sacrificer (rare but class.): ut se exta ad immolatoris fortunam accommodent, Cic. Div. 2, 15, 36: nati immolator unici, Prud. Cath. 12, 48.