Middle Primitive Elvish
solos
noun. surf
khar
root. helmet
kharan
root. helmet
kharap
root. helmet
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 Etymologies of the 1930s glossed “helmet” with extended forms √KHÁRAP and √KHÁRAN (EtyAC/KHAR); one of its derivatives ᴹQ. Eldahar seems to be a precursor to Q. Eldacar “Elfhelm”. There are many other words for “helmet” in Tolkien’s later writing, and this root was probably abandoned.