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.

Qenya 

perina

adjective. *halved

perya-

verb. to divide in middle, halve

A verb in The Etymologies of the 1930s based on the root ᴹ√PER “divide in middle, halve”, so probably of similar meaning (Ety/PER). It was followed by a form ᴹQ. perina which might be a passive participle (“✱halved”) or an ordinary adjective (“✱half”), as with N. perin “half”.

Neo-Quenya: For purposes of Neo-Quenya, I prefer to use later Q. peresta for “half”, so I assume perina is (in Quenya) a passive participle meaning “halved”.

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.