Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
incīsim, adv. [incisus, from 2. incīdo], in short clauses (very rare): haec quidem duo binis pedibus incisim; deinde membratim, etc. (shortly before: incise membratimve), Cic. Or. 63, 213: incisim et membratim tractata oratio, id. ib. 67, 225.