Lewis & Short

rĕ-languesco, gŭi, 3, v. inch. n., to sink down fainting; to grow languid or faint (class. but rare).

  1. I. Lit.: (soror) Imposito fratri moribunda relanguit ore, Ov. M. 6, 291.
      1. 2. Transf., of the wind, to sink, slacken, lull, abate, Sen. Q. N. 5, 8, 3.
        Of a star, to grow dim, Plin. 37, 9, 51, § 134.
  2. II. Trop., to become enfeebled or relaxed, to relax: quod iis rebus relanguescere animos eorum et remitti virtutem existimarent, * Caes. B. G. 2, 15: quod autem relanguisse se dicit, that he has relaxed (in his enmity), * Cic. Att. 13, 41; cf.: animo relanguit ardor, Ov. Am. 2, 9, 27: ut taedio impetus relanguescat regis, Liv. 35, 44 (relanguerat, v. l. for elanguerat, Tac. H. 1, 46): si prima indignatio relanguescat, id. ib. 1, 33.