Lewis & Short

pinguesco, ĕre, v. inch. n. [pinguis], to become or grow fat.

  1. I. Lit.: emaciatum armentum medicā (herbā) pinguescit, Col. 2, 11, 2: attilus (piscis) in Pado inertiā pinguescens, Plin. 9, 15, 17, § 44; 18, 14, 36, § 134: frumenta pinguescunt, id. 17, 2, 2, § 15: campos sanguine, grow fertile, Verg. G. 1, 492.
  2. II. Transf.
    1. A. To grow fat, rich, or oily: vinum Maroneum vetustate pinguescit, Plin. 14, 4, 6, § 54: nuces juglandes, id. 19, 5, 30, § 95.
    2. B. To become shining, like fat: achates politurā pinguescit, Plin. 37, 10, 65, § 177.
    3. C. To aspirate in speaking: Aeolenses Graeci, in quibusdam dictionibus, ut pinguescant, digamma apponunt ut pro Elena dicunt Velena, Serg. p. 1827 P.
  3. III. Poet., to increase, grow more violent: flammae pinguescunt, Sil. 7, 354.