The verb N. hadh- “sit” appeared in The Etymologies of the 1930s under the root ᴹ√KHAD of the same meaning, but the verb and its root were revised to N. haf- and ᴹ√KHAM (Ety/KHAM; EtyAC/KHAM).
Neo-Sindarin: In Tolkien’s later writings √KHAD “sit” was restored, so I would use ᴺS. hadh- “to sit” for purposes of Neo-Sindarin; compare the 1969 verb S. hadhwa- “to seat” < ✶khadmā (PE22/148).
Conceptual Development: The Gnomish Lexicon of the 1910s had G. hag- “sit, sit down” (GL/47).
A noun in The Etymologies of the 1930s for “garment” derived from the root ᴹ√KHAP “enfold” (Ety/KHAB).
Conceptual Development: Earlier garment words include G. baith “a garment” from the Gnomish Lexicon, ᴱN. baith “clothes, garments, dress” in Early Noldorin word lists of the 1920s (PE13/138) and ᴱN. gwab “garment” in both Early Noldorin word lists and the Early Noldorin Grammar of the 1920s (PE13/123, 146). The collective plural ᴱN. gwablith of this last word was also used for “clothes”.
See N. hammad “clothing” for other similar words.