Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
immordĕo (inm-), sum, 2, v. a. [inmordeo], to bite into (poet. and rare; perh. only in part. perf. pass.): labitur, immorsaque cadens obmutuit hasta, Stat. Th. 2, 628: immorso aequales videant mea vulnera collo, Prop. 3, 8 (4, 7), 21: (stomachus) pernā magis ac magis hillis Flagitat immorsus refici (= vellicatus, excitatus), excited, Hor. S. 2, 4, 61.