Early Primitive Elvish
pipi
root. hang, trail
kiniki Reconstructed
root. hang
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.
A root in the Qenya Lexicon of the 1910s glossed “hang, trail”, with derivatives like ᴱQ. pint (pimp-) “tail” and ᴱQ. pipte- “fall (of folds or clusters), hang, trail” (QL/74). There are no signs of this root in Tolkien’s later writing, but I think it is worth retaining as a Neo-Eldarin root to serve as the basis for “tail” words.