Gnomish
tol
noun. isle (with high steep coast)
tol erethrin
place name. Lonely Isle
tol withernon (ar lim gardhin arthi)
*island of Withernon and many places besides
mineth
noun. island
uvin
noun. eight
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 word in the Gnomish Lexicon of the 1910s glossed “island” (GL/57), probably connected to the root ᴱ√MINI in the contemporaneous Qenya Lexicon as suggested by Christopher Tolkien, as it was the basis of other words for raised objects like ᴱQ. mindon “turret” (LT1A/Minethlos; QL/061).