Quenya
hru-
verb. hru-
hru-
prefix. evil-
ru-
prefix. evil-
Sindarin
rhu-
prefix. evil-
rhû
matter
rhû
noun. matter
A Sindarin word appearing as {hrū >} rhû “matter” in Quenya Notes (QN) from 1957, cognate to Q. hrón “flesh/substance of Arda, matter” and derived from srōn < √SRON, a root variation of √RON “solid, tangible, firm”. In later writings Tolkien revised its Quenya cognate to {orma} > erma (MR/218, 231 note #26, 338, 359 note #14).
Neo-Sindarin: I would retain S. rhû for “matter”, and would assume it was of independent derivation from its Quenya equivalent.
Beware, older languages below! The languages below were invented during Tolkien's earlier period and should be used with caution. Remember to never, ever mix words from different languages!
Early Noldorin
bal-
prefix. evil-
hru-, hrú, ru- prefix implying wickedness or evil, only occasionally used, e.g. hrúcarë, q.v.