An adjective glossed “awkward, hard” in Definitive Linguistic Notes (DLN) from 1959 derived from the root √SRAK, a variant of √SRAG (PE17/154).

Neo-Sindarin: I believe that S. rhanc has the connotation of “difficult due to some resistance or obstacle”; compare Q. hranga- “thwart”. It can be contrasted with dîr, which I use to mean “difficult due to the complexity of the task” for purposes of Neo-Sindarin.

Conceptual Development: On a rejected page from DLN, rhae < √SRAY was glossed “easy” rather than “difficult” (PE17/172). See the entry as(a)- for a discussion of the conceptual development of words for “easy”.

A much earlier word of similar meaning and derivation to rhanc “difficult” is G. arc “fierce, harsh, ill tempered; awkward, difficult” appearing in the Gnomish Lexicon of the 1910s where it was derived from ᴱ✶r̄k- (GL/20), a root similar to √SRAK. The gap in time makes it hard to say if the two were related conceptually. The Gnomish word may instead have evolved conceptually into N. tara and S. tarch (both meaning “tough, stiff”); see those entries for discussion.