Probably an error. 偶奇性 is in other dictionaries, 奇偶性 is nowhere to be found. (I only found 奇偶核 and 奇偶検査.)
Ok I only now realized that 奇遇 is different from 奇偶. I shouldn't be on forums after 9pm. With 奇遇's meaning being completely different, it's increasingly unlikely that 奇遇性 means "parity".
@buffalocat If you click on "Links" on the left hand side of the entry, and then "Edit in JMDict" you can send in suggestions for corrections directly to the editors of the underlying dictionary file that Jisho uses. Once they have revised the entry there it will also show up on Jisho.
偶奇性 is parity in physics. 奇偶性 is parity in a computing context. ( 奇遇性 is a typo.)
Is this word correct?
I'd think that "parity" would be written 奇偶性, though googling that doesn't bring up anything (in Japanese, anyway). Incidentally, the wikipedia page for parity uses 偶奇性. So is this an error in the dictionary, or something else?