What is an odd prime?
$2$ is an even prime, so "odd prime" is a short-hand for "a prime not equal to $2$".
Ummm. I remember Michio Kuga saying “There are two types of primes, odd and even, and they cause the same amount of trouble.”
Irving Kaplansky was fond of quoting Marshall Hall about this: “It’s not that 2 is so small. It’s that it’s so even.”
From page xviii in T.Y.Lam, Introduction to Quadratic Forms over Fields:
A mathematician said “Who
Can quote me a theorem that's true?
For the ones that I know
Are simply not so
When the characteristic is two!”