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.
mekilwa
adjective. central
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.
entya
central, middle
entya, enetya adj. "central, middle" (VT41:16; these forms, as well as the noun entë "centre", come from a late, somewhat confused source; the adjective #endëa and the noun endë from earlier material may fit the general system better, and #endëa is even found in the LotR itself as part of the word atendëa, q.v.)
A word for “central” in the Qenya Lexicon of the 1910s, an adjectival form of ᴱQ. metl (mekil-) “centre” (QL/60).