An adjective in The Etymologies of the 1930s glossed “naked” and derived from primitive ᴹ✶skelnā under the root ᴹ√SKEL (Ety/SKEL). This word was originally hall “naked” under an earlier but deleted form of the root ᴹ√SKAL (EtyAC/SKEL). The root ᴹ√SKEL was also the basis for the verb N. heltha- “to strip”, and its Quenya derivative ᴹQ. helda was at one point was glossed “stripped bare” (Ety/SKAL¹), so the word hell seems to mean “naked” in the sense “✱stripped (of clothing or other covering)”.
Conceptual Development: There are a couple of earlier “naked” words in the Gnomish Lexicon of the 1910s that seems to be similarly derived. G. dautha “naked, stripped” was related to daf- “to strip, flay” (GL/29) and G. hulc “naked” (GL/49) is like the cognate of ᴱQ. hulqa “naked” under the early root ᴱ√HULU “strip” (QL/41). In later writings, some “naked” words were derived from √PAR “peel” instead (PE17/86, 171).
An adjective in The Etymologies of the 1930s glossed “veiled, hidden, shadowed, shady” derived from the primitive ᴹ✶skalnā > ON. skhalla under the root ᴹ√SKAL “screen, hide (from light), overshadow” (Ety/SKAL¹).