Lord of Doriath whose name was translated “Greymantle” (S/56) or “Greycloak” (WJ/410), a combination of thind “grey” (SA/thin(d)) and the lenited form of coll “cloak”.
Conceptual Development: In earliest Lost Tales, this name appeared variously as G. Tintoglin (LT1/131), G. Tinthellon or Tinto’ellon (LT2/50, 61) and G. Tinwelint, the last of these being his most common name in the early tales (LT1/115, LT2/50, GL/70). The name Thingol emerged in the Lays of Beleriand from the 1920s (LB/9) and was used thereafter. In Early Noldorin notes from this period, ᴱN. Thingol contained the word ᴱN. thing “prince” (PE13/154).
In The Etymologies from the 1930s, the name Thingol was designated Doriathrin [Ilkorin], and its second element was first Ilk. gôl “light” (Ety/KAL) and then Ilk. (n)gôl “wise” (Ety/THIN). In Silmarillion revisions from the 1950s-60s, the later meaning of his name “Greycloak” emerged along with its Quenya equivalent Sindicollo (MR/217).
prop. n. 'Grey-cloak'. Q. Sindacollo, Sindikollo. >> thin, thind, thinn