Meaning

verb to incline or bend from a vertical position

adjective lacking excess flesh; ; -Shakespeare

noun the property possessed by a line or surface that departs from the vertical

originFrom Middle English lene (“lean”), from Old English hlǣne (“lean”), (cognate with Low German leen), perhaps from hlǣnan (“to cause to lean (due to hunger or lack of food)”), from Proto-Germanic *hlainijaną (“to cause to lean”). If so, then related to Old English hlinian, hleonian (“to lean”). Compare Old Norse linr (“mild; soft, limp; weak”), Old High German len (“mild”).

Etymology from Wiktionary, CC BY-SA 3.0