kemen noun "earth"; see cemen.
mar (1) noun "earth" (world), also "home, dwelling, mansion". Stem mard- (VT46:13, PE17:64), also seen in the ablative Mardello "from earth" (FS); the word is used with a more limited sense in oromardi "high halls" (sg. oromar, PM17:64), referring to the dwellings of Manwë and Varda on Mt. Taniquetil (Nam, RGEO:66). The initial element of Mardorunando (q.v.) may be the genitive mardo (distinguish mardo "dweller"). May be more or less identical to már "home, house, dwelling" (of persons or peoples; in names like Val(i)mar, Vinyamar, Mar-nu-Falmar, Mardil) (SA:bar, VT45:33, VT47:6). Már is however unlikely to have the stem-form mard-; a "Qenya" genitive maren appears in the phrase hon-maren, q.v., suggesting that its stem is mar-. A possible convention could therefore be to use már (mar-) for "home, house" (also when = household, family as in Mardil, q.v.), whereas mar (mard-) is used for for "earth, world". Early "Qenya" has mar (mas-) "dwelling of men, the Earth, -land" (LT1:251); notice that in LotR-style Quenya, a word in -r cannot have a stem-form in -s-.
cemiearth, soil, land
cemi noun "earth, soil, land"; Cémi ("k")"Mother Earth" (LT1:257; the "Qenya" word cemi would correspond to cemen in LotR-style Quenya)