Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
inter-sisto, stĭti, 3, v. n., to stand still in the middle; trop., to stop in the midst, to make a pause in speaking (perhaps only in Quint.); of a speaker: indecentissime, Quint. 8, 3, 45: ut intersistat fatigatus, id. 12, 11, 2; 10, 7, 10; of discourse: oratio, id. 9, 4, 33.
Pass. impers.: quasi intersistatur, Quint. 9, 4, 36; so, ubi clausulis non intersistitur, id. 9, 4, 106.