Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
rĕ-tinnĭo, īre, v. n., to ring again, resound, Varr. R. R. 2, praef. § 2: in vocibus nostrorum oratorum retinnit quiddam et resonat urbanius, Cic. Brut. 46, 171.