Lewis & Short

mollesco, ĕre, v. inch. n. [molleo], to become soft, to soften (poet. and in post-Aug. prose; cf. liquesco).

  1. I. Lit.: rura colit nemo: mollescunt colla juvencis, Cat. 64, 38: ebur, Ov. M. 10, 283: tactu, Plin. 12, 17, 37, § 76.
  2. II. Trop.
      1. 1. To become soft, mild, or gentle: tum genus humanum primum mollescere coepit, Lucr. 5, 1014: pectora, Ov. P. 1, 6, 8.
      2. 2. To become effeminate, unmanly: mollescat in undis, Ov. M. 4, 386: ne forte mollescat cor vestrum, Vulg. Jer. 51, 46.