- lean (adj.)
- "thin, spare, with little flesh or fat," c. 1200, from Old English hlæne "lean, thin," possibly (Skeat) from hlænan "cause to lean or bend," from Proto-Germanic *khlainijan, which would connect it to Old English hleonian (see lean (v.)). But perhaps rather, according to OED, from a PIE *qloinio- (with cognates in Lithuanian klynas "scrap, fragment," Lettish kleins "feeble"). Extended and figurative senses from early 14c.
- lean (n.2)
- c. 1200, "lean animals or persons," from lean (adj.). Meaning "lean part of anything, muscle without fat, lean meat" is mid-15c.
- lean (n.1)
- "action or state of leaning, deviation from a vertical position," 1776, from lean (v.).
- lean (v.)
- c. 1200, from Old English hlinian "to recline, lie down, rest; band or incline" (Mercian hleonian, Northumbrian hlionian), from Proto-Germanic *khlinen (source also of Old Saxon hlinon, Old Frisian lena, Middle Dutch lenen, Dutch leunen, Old High German hlinen, German lehnen "to lean"), from PIE root *klei- "to lean, to incline" (source also of Sanskrit srayati "leans," sritah "leaning;" Old Persian cay "to lean;" Lithuanian slyti "to slope," slieti "to lean;" Latin clinare "to lean, bend," clivus "declivity," inclinare "cause to bend," declinare "bend down, turn aside;" Greek klinein "to cause to slope, slant, incline;" Old Irish cloin "crooked, wrong;" Middle Irish cle, Welsh cledd "left," literally "slanting").
Transitive sense "cause to lean or rest" is from 14c. Meaning "to incline the body against something for support" is mid-13c. Figurative sense of "to trust for support" is from early 13c. Sense of "to lean toward mentally, to favor" is from late 14c. Related: Leaned; leaning. Colloquial lean on "put pressure on" (someone) is first recorded 1960.