c. 1200, "feeling of relief in affliction or sorrow; solace, consolation" (as still in take comfort); also "source of alleviation or relief;" from Old French confort "consolation, solace; pleasure, enjoyment," from conforter "to solace; to help, strengthen" (see comfort (v.)). An Old English word in the same sense was frofor. Meaning "state of enjoyment resulting from satisfaction of bodily wants and freedom from anxiety" is from mid-13c. Also in Middle English "strength, support, encouragement" (late 14c.). Comforts (as opposed to necessities and luxuries) is from 1650s. Comfort food "food that provides a nostalgic or sentimental value but typically is of dubious nutritional value" is by 1987.
word-forming element meaning "lacking, cannot be, does not," from Old English -leas, from leas "free (from), devoid (of), false, feigned," from Proto-Germanic *lausaz (cognates: Dutch -loos, German -los "-less," Old Norse lauss "loose, free, vacant, dissolute," Middle Dutch los, German los "loose, free," Gothic laus "empty, vain"), from PIE root *leu- "to loosen, divide, cut apart." Related to loose and lease.
<a href="https://www.etymonline.com/word/comfortless">Etymology of comfortless by etymonline</a>
Harper, D. (n.d.). Etymology of comfortless. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/comfortless