zestless

adj

Etymology: From zest + -less.

1. Lacking zest; passionless, unenthusiastic.

   “1792, Robert Sadler, Wanley Penson, or The Melancholy Man, London: C. & G. Kearsley, Volume 3, p. 252, There are moments, indeed, in which I could be pleased to repay even a zestless joke with a smile, and, to feed the cheerfulness of a companion, rummage my own recollection for a mirthful incident; but, alas! ’tis not so now—My soul is too much absorbed in its own gloomy ruminations, to be drawn forth by its accustomed urbanity […]”

   “1865, Charles Heavysege, Jephthah’s Daughter, Montreal: Dawson Brothers, IV, (unpaginated), […] So he passes To second childhood; but, as quickening gases, Being fled, leave zestless a once cheering draught, We grow not merry though the Dotard laughed.”