sole

From Middle English sole, soule, from Old French sol, soul (“alone”), from Latin sōlus (“alone, single, solitary, lonely”). Ultimately from Proto-Indo-European swé (reflexive pronoun). Perhaps related to Old Latin sollus (“whole, complete”), from Proto-Indo-European solh₂- (“safe, healthy”). More at save.

From Middle English sole, soole, from Old English sole, solu. Reinforced by Anglo-Norman sole, Old French sole, from Vulgar Latin sola (“bottom of the shoe”, also “flatfish”), from Latin solea (“sandal, bottom of the shoe”), from Proto-Indo-European swol- (“sole”). Cognate with Dutch zool (“sole, tread”), German Sohle (“sole, insole, bottom, floor”), Danish sål (“sole”), Icelandic sóli (“sole, outsole”), Gothic 𐍃𐌿𐌻𐌾𐌰 (sulja, “sandal”). Related to Latin solum (“bottom, ground, soil”). More at soil. Compare typologically Russian по́чва (póčva) akin to подо́шва (podóšva).

From Middle English sole, soole, from Old English sāl (“a rope, cord, line, bond, rein, door-hinge, necklace, collar”), from Proto-Germanic sailą, sailaz (“rope, cable”), sailō (“noose, rein, bondage”), from Proto-Indo-European sey- (“to tie to, tie together”). Cognate with Scots sale, saile (“halter, collar”), Dutch zeel (“rope, cord, strap”), German Seil (“rope, cable, wire”), Icelandic seil (“a string, line”). Non-Germanic cognates include Albanian dell (“sinew, vein”).

From Middle English sol, from Old English sol (“mire, miry place”), from Proto-Germanic sulą (“mire, wallow, mud”), from Proto-Indo-European sūl- (“thick liquid”). Cognate with Saterland Frisian soal (“ditch”), Dutch sol (“water and mud filled pit”), German Suhle (“mire, wallow”), Norwegian saula, søyla (“mud puddle”). More at soil.

From earlier sowle (“to pull by the ear”). Origin unknown. Perhaps from sow (“female pig”) + -le, as in the phrase "take a sow by the wrong ear", or from Middle English sole (“rope”). See above.