Lewis & Short

prō-serpo, ĕre, v. n., to creep forwards or forth, to creep or crawl along (ante- and post-class.).

  1. I. Lit.: proserpens bestia, Plaut. Poen. 5, 2, 74; cf. id. As. 3, 3, 105; id. Pers. 4, 28; Varr. L. L. 5, § 68 Müll.: servulus proserpit leniter, App. M. 4, p. 151, 13: de specu funesta proserpit ursa, id. ib. 7, p. 198, 25.
    Transf., of plants, to come forth imperceptibly: sata in lucem proserpunt, Arn. 3, 119.
  2. II. Trop., to move on imperceptibly, to glide or steal along (postclass.): proserpit ad intima vulnus, Ser. Samm. 14, 251: malo proserpenti occurrere, Amm. 15, 8, 7.