Lewis & Short

tĕpesco, pŭi, 3, v. inch. n. [tepeo], to become moderately warm, lukewarm, or tepid.

  1. I. To grow warm: maria agitata ventis ita tepescunt, ut, etc., * Cic. N. D. 2, 10, 26; Cels. 3, 6 med.; Ov. M. 3, 412: nostra tepescit aqua, id. P. 3, 4, 56: fixo ferrum in pulmone tepescit, Verg. A. 9, 701; Mart. 6, 59, 4 al.
  2. II. To grow cool (rare).
    1. A. Lit., Mart. 2, 1, 10.
    2. B. Trop., to cool off, decrease in ardor: paulatim fugit ira ferox mentesque tepescunt, Luc. 4, 284: negotio tepescente, Amm. 28, 1, 9: cum omnes amicitiae Romae tepescant, id. 28, 4, 21: veneres tepuere sub annis, Nemes. Ecl. 1, 13.