Early Quenya
karo
noun. deed, act, action
kar
noun. head
karo ohtan
a deed of (some actual) war
kas
noun. head, top, summit
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.
karo
noun. deed, act, action
kar
noun. head
karo ohtan
a deed of (some actual) war
kas
noun. head, top, summit
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.