Not either one of two.

Similarly not.

not one or the other; not either; none of two things

(colloquial) Used to say that a negative-containing statement of the previous speaker applies to the speaker as well.

used for showing that something is not true of two or more people, things, actions, qualities, or ideas (This entry is a translation hub.)

(idiomatic) Having no influence or significance on the issue at hand.

It is not good to borrow money from anybody, lest you will lose their trust and friendship.

Alternative form of neither fish, flesh, nor good red herring

(idiomatic) Something or someone which is not easily categorized; something or someone that does not rightly belong or fit well in a given group or situation.

To fail to make head or tail of; not to understand at all.