Qenya
perina
adjective. *halved
perya-
verb. to divide in middle, halve
Beware, older languages below! The languages below were invented during Tolkien's earlier period and should be used with caution. Remember to never, ever mix words from different languages!
A verb in The Etymologies of the 1930s based on the 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”.