Early Noldorin
esg
noun. sharp upstanding rock in water, sharp upstanding rock in water; [G.] sharp point, sharp edge
esk
noun. sharp upstanding rock in water
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.
This noun appeared in the Gnomish Lexicon of the 1910s as G. esc “sharp point, sharp edge” (GL/31), related to G. aisc “sharp, bitter; sharp edge of a blade” (GL/18), and derived from the early root ᴱ√eke or one of its variants eχe or aχa (GL/31). In Early Noldorin Word-lists of the 1920s there was a similar word ᴱN. esk or esg “sharp upstanding rock in water”, the first of these probably an archaic form with sk > sg (PE13/143).