Metas seem to be all the rage nowadays, so I'm jumping on the bandwagon. Hoping it's not too obtuse. Best of luck!
A couple hints, of varying degrees of usefulness:
1. Consider the four longest Across entries. They each clue another word.
2. The title hints at something that isn't quite even; in this case, it's related to, but not exactly, the even numbers.
3. How might the words MOO and MIX relate to even numbers?