Old English lam "clay, mud, clayey or muddy earth," from Proto-Germanic *laimaz (source also of Old Saxon lemo, Dutch leem, German Lehm "loam"), from PIE root *(s)lei- "slimy" (source also of Latin limus "mud;" see slime (n.)).
In early use also the stuff from which God made man in His image. As the technical name for a type of highly fertile clayey soil, it is attested from 1660s. As a verb from c. 1600. Related: Loamed; loaming. Loamshire as a name for an imaginary typical rural English county is from "Adam Bede" (1859).
"muddy, covered with clay," from Latin lutosus, from lutum "mud, dirt, mire, clay," from Proto-Italic *luto-, *lustro-, from PIE *l(h)u-to- "dirt," *l(h)u-(s)tro- "dirty place," from root *leu- "dirt; make dirty" (cognates: Greek lythron "gore, clotted blood," lyma "dirty water; moral filth, disgrace," lymax "rubbish, refuse," lyme "maltreatment, damage;" Latin lues "filth;" Old Irish loth "mud, dirt;" Welsh lludedic "muddy, slimy; Albanian lum "slime, mud;" Lithuanian liūtynas "loam pit").
Hence also English lute (n.) as a type of tenacious clay or cement used to stop holes, seal joints, etc. (c. 1400), from Old French lut or Medieval Latin lutum, from the Latin noun. Lute also was a verb in English.