Lewis & Short

ob-rĭgesco, găi, 3, v. inch. n., to stiffen, become stiff (class.).

  1. I. Lit.
        1. a. With abl.: pars obrigescit frigore, Lucil. ap. Non. 97, 12: pars (terrae regionum) obriguerit nive, pruināque, Cic. N. D. 1, 10, 24; and: e quibus (cingulis) duos obriguisse pruinā vides, id. Rep. 6, 20, 21.
        2. b. Absol.: fructus per pruinam obriguerint, Pac. ap. Varr. L. L. 6, § 6 Müll. (acc. to Trag. Rel. p. 64 Rib.): cum jam paene obriguisset, vix vivus aufertur, Cic. Verr. 2, 4, 40, § 87: obrigesceret cum gladio, become stiff with holding, Vulg. 2 Reg. 23, 10.
  2. II. Trop., to grow hard, become hardened: viro non vel obrigescere satius est? Sen. Ep. 82, 2.