A root glossed “pluck” in the Quenya Verbal System (QVS) from 1948 serving as the basis for ᴹQ. ruk- of the same meaning (PE22/102), but mentioned nowhere else with this given meaning.
Middle Primitive Elvish
tug
root. *muscle
ruk
root. pluck
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.
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.
An unglossed root in The Etymologies of the 1930s with derivatives like ᴹQ. tuo/N. tû “muscle, sinew; vigour, physical strength” and ᴹQ. tunga/N. tong “taut, tight (of strings, resonant)” (Ety/TUG). It was also the basis for the name N. Tuor “strength-vigour”, the only place where this name was given a clear etymology, though later Tolkien decided this name was actually from the language of the Edain (PM/348, 364 note #49).