אִיס־, a prefix for the formation of (verbal) nouns (Ispeel nouns), affecting the first radical in the same way as the prefix of the Hithpa. or Ithpe.; e.g. from סגי, אִסְטַגְיוֹת (pl.) rims; from סוַר = שור to walk, stride, אִיסְתְּוָורָא ankle, &c. Before dentals איס and אס interchange with אִיצְ־ and אִצְ־. [Words not found under איס־ must be looked for under אִס־ and vice versa.]