pīlu, pēlu, pūlu - limestone (CAD P 380, AHw 864)

No definitive etymology can be suggested. As argued by Greppin 1991, 204, the Akk. word is likely to be connected with Armenian buṙ “plaster, lime” (AB I 485; the Armenian word was further borrowed into Turkish, see Dankoff 1995, 31 f.), Greek πῶρος (Liddell; Scott 1561b; no Indo-European etymology in Frisk II 635), Urartian pulusi “stele” (the Urartian word can be analysed as the stem pul- and the suffix -usə, see Wilhelm 2008b, 112). According to Greppin, we are probably dealing with a “wandering word”, perhaps of “Anatolian or Mesopotamian origin”.