obrepto

obrepto, āvi, 1, v. freq. n. [id.], to steal on unawares, to come on imperceptibly (very rare):

ne quis obreptaverit,

Plaut. Pers. 1, 2, 27:

obreptantibus Satyris,

Plin. 35, 10, 36, § 109 (but in Cic. Att. 6, 5, 3, the correct read. is obrepebat).