Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
inter-for, fātus sum, 1, v. dep. n. and a. (interfari, interfatur, interfatus are the forms in common use), to speak between, to interrupt in speaking (syn. interpello): priusquam ille postulatum perageret, interfatur Appius, Liv. 3, 47: orsum eum dicere, Phaeneas interfatus, interrupted, id. 32, 34: Venus sic interfata est, Verg. A. 1, 386: quem interfari nefas est, Plin. Ep. 1, 23, 2.