Lewis & Short

insĭnŭātĭo, ōnis, f. [insinuo], an entrance through a narrow or crooked way.

  1. I. Lit.: Ponti, Avien. Perieg. 397.
  2. II. Trop.
    1. A. An insinuating or ingratiating one’s self into the favor of others: exordium in duas partes dividitur, in principium et insinuationem. … Insinuatio est oratio, quadam dissimulatione et circuitione obscure subiens auditoris animum, Cic. Inv. 1, 15, 20.
    2. B. A notification, publication, Cod. Just. 8, 54, 32.