Lewis & Short

surreptīcĭus (subr-) or -tĭus, a, um, adj. [surripio], stolen, surreptitious (Plautin.).

  1. I. Lit.: puer, Plaut. Men. prol. 60: puellae ingenuae, id. Poen. 5, 2, 2.
  2. * II. Trop., concealed, clandestine: amor, Plaut. Curc. 1, 3, 49.