The word ᴱQ. sornion “eyrie” appeared in the Qenya Lexicon of the 1910s as an elaboration of ᴱQ. sor(ne) “eagle” (QL/86). The word also appeared in the contemporaneous Poetic and Mythological Words of Eldarissa (PME/86).

Neo-Quenya: Since Q. soron, sorno or sorne were words for “eagle” in Tolkien’s later writings, I think ᴺQ. sornion “eyrie” can be retained for purposes of Neo-Quenya, perhaps originally a genitive plural “of the eagles”.