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.
nahta
noun. bite
nahta
cardinal. eighteen
A specialized word for “eighteen” that was part of a duodecimal system of counting in notes from the 1930s, derived from ᴹ√nakat (PE14/17 note #6).
Conceptual Development: The Early Qenya Grammar of the 1910s had ᴱQ. hualqe “eighteen” and adjective ᴱQ. hual(qe)tya “eighteenth” beside the more ordinary but rarer form ᴱQ. tolkea (PE14/49, 82). The word hualque is perhaps another specialized duodecimal word meaning “✱double nine” as a combination of ᴱQ. hue “nine” and the dual root ᴱ√WI.
nahta-
verb. to slay
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 bite” in The Etymologies of the 1930s under the root ᴹ√NAK of the same meaning (Ety/NAK).