Lewis & Short

dūrāmentum, i, n. [duro], a hardening in concreto.

  1. I. Lit., a hardened, i. e. ligneous vine-branch, Col. 4, 21, 1; Plin. 17, 23, 35, § 208; Pall. Febr. 12, 1.
    Called also duramen, Col. 4, 22, 1.
  2. II. Transf., a means of hardening, stimulus: humanae imbecillitatis efficacissimum duramentum est necessitas, Val. Max. 2, 7, 10.
  3. III. Trop., firmness (with robur), Sen. Tranq. An. 1.