A noun in The Etymologies of the 1930s glossed “hound” derived from primitive ᴹ√KHUGAN; in the second version of this entry the root became ᴹ√KHUG “bark, bay” and Tolkien only said that N. Huan was a dog-name, though its cognate ᴹQ. huan still meant “hound” (Ety/KHUGAN). This word was indeed used as the name of the great Valinorian hound Huan, which Tolkien established very early (LT2/21) and retained for his entire life (S/142).

Possible Etymology: It is hard to explain why the primitive short ŭ in huan did not become o as usual in Noldorin and Sindarin. Perhaps the primitive form was actually *khūgan in the Noldorin/Sindarin branch of the language. Tolkien did frequently write the name as Húan in later writings (RS/183; WJ/62 and forward).

Conceptual Development: In Tolkien’s earliest writings, ᴱQ. huan “dog” was a Qenya word, and its nearest Gnomish equivalents were G. hû “dog” and G. saur “hound, wild dog” (GL/49, 67), all derived from the early root ᴱ√SAẆA (QL/82). The form ᴱN. fand or fan “dog” appearing in Early Noldorin Word-lists of the 1920s was probably also related (PE13/143). By The Etymologies of the 1930s, it seems Huan was a Noldorin name, and it may have remained so in Sindarin of the 1950s and 60s, but since its Quenya form was identical it is hard to know for sure.