"languid and unresponsive, slothful," mid-15c., from Middle English liste "pleasure, joy, delight" (see list (v.4)) + -less. Spenser, if no one else, tried listful (1590s). Related: Listlessly; listlessness.
"to be pleased, desire" (intransitive), a sense now archaic, mid-12c., lusten, listen "to please, desire," from Old English lystan "to please, cause pleasure or desire, provoke longing," from Proto-Germanic *lustjan (source also of Old Saxon lustian, Dutch lusten "to like, fancy," Old High German lusten, German lüsten, Old Norse lysta "desire, wish, have a fancy"), from *lustuz-, from PIE root *las- "to be eager, wanton, or unruly" (see lust (n.)). Related: Listed; listing.
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.
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<a href="https://www.etymonline.com/word/listless">Etymology of listless by etymonline</a>
Harper, D. (n.d.). Etymology of listless. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/listless