The Quenya equivalent of the Sindarin name S. Thingol, more frequently appearing in its shorter form Singollo. This name is a compound of sinda “grey” (SA/thin(d), PE17/72) and collo “cloak” (SA/thin(d)).
Conceptual Development: Tolkien vacillated between this name and the form Sindicollo (MR/217; NM/239; PM/337; WJ/410) for the full Quenya name of Thingol. This probably reflected uncertainty over the proper form of the Quenya adjective for “gray”: sindë (sindi-) versus sinda. Chistopher Tolkien used the form Sindacollo in The Silmarillion index and appendix. Most of the time, though, Tolkien used Singollo instead of either of the longer forms.
Sindicollo (þ) noun "Grey-cloak", title of Elwë (Elu). Sindarin Thingol. (WJ:410, MR:217).(Sindi- in this name is a compound form of sindë, q.v.) Original form Thindicollo (WJ:333). The Silmarillion appendix (SA:thin(d) ) gives Sindacollo.