ᴱ√SITI root. “*custom, habit”
An unglossed root in the Qenya Lexicon of the 1910s with variants ᴱ√SITI and ᴱ√SIT-U and derivatives like ᴱQ. sitsina “habitual, customary” and ᴱQ. situ- “am accustomed” (QL/84). There are no signs of this root in Tolkien’s later writing, but I think it is worth positing a Neo-Root ᴺ√SIT to salvage some of these early words.
References ✧ QL/84