obreption (n.)

"the obtaining or trying to obtain something by craft or deception," 1610s, from Latin obreptionem (nominative obreptio)  "a creeping or stealing on," noun of action from past-participle stem of obrepere "to creep on, creep up to," from ob "on, to" (see ob-) + repere "to creep" (see reptile). Opposed to subreption, which is to obtain something by suppression of the truth. Related: Obreptious.