There are more words but they are from Tolkien's earlier conceptional periods. Tolkien likely changed these words as he evolved the aesthetics and completeness of the languages. You may even find languages that Tolkien later rejected. Do not mix words from different time periods unless you are familiar with the phonetic developments.
rista-
verb. to cut
rista
noun. cut
narka-
verb. to rend
A verb in The Etymologies of the 1930s glossed “to rend” derived from the root ᴹ√NARAK “tear, rend (tr. and intr.)” (Ety/NÁRAK; EtyAC/NÁRAK). In The Etymologies as published in The Lost Road Christopher Tolkien gave the form as narki (LR/375), but Carl Hostetter and Patrick Wynne corrected this to narka in their Addenda and Corrigenda to the Etymologies (VT45/37).
Below: Tolkien's Late Period (1950–1973). These are from Tolkien's late conceptual period — his most settled forms of the languages. Prefer these over the earlier ones above when composing new text.
A noun for “a cut” in The Etymologies of the 1930s under the root ᴹ√RIS “slash, rip” (Ety/RIS). It was also an element the name ᴹQ. Latimberista, Quenya equivalent of S. Imladris, in a page of rejected notes from 1948 (PE22/127). It might reappear in some later notes as well; see Q. rista- “to cut” for further discussion.