full meanings of apiori and a posteriori?

The other answer is correct: "A priori knowledge or justification is independent of experience (for example "All bachelors are unmarried").

"Whatever is pure a priori is unmixed with anything empirical. In Kant's doctrine, all the necessary conditions of experience (i.e., forms and categories) are a priori. Whatever is a priori must possess universal and necessary validity. Sometimes used loosely to designate anything non-empirical, or something which can be known by reason alone."

http://www.ditext.com/runes/a.html

But this is a false designation of something in the mind. Nothing can be independent of experience. To know that all bachelors are unmarried, you must first have sensory experience of either hearing a description of both subjects, or reading about it, or at least of knowing something related to them that allows you to deduce other things that brings you to the conclusion--in which case you had would have had sensory experience about "something" related "to something". You cannot deduce that all bachelors are unmarried if you were born with no sensory equipment.

To think that anything like knowledge of universals could be "a priori" in your mind takes us back to the most famous example, Plato, who said we came to have our knowledge by passing through "the world of universals" which were in the real of the gods in heaven; and passing by them on our way to being born we somehow knew all that we had to know, and then our experiences here on earth allowed us to connect them to those universals already "somehow" in our minds.

Kant and Hegel thought the same thing (but not about the world of the gods etc). Since we are born tabula rasa, it is necessary to understand that universals are "abstracted" from our experiences. We cannot know the universal called 'table' for example until we have experienced several forms of it, in order to see that universal in each of them.

A priori and a posteriori are therefore non existent. They are improper categories. The only kind of knowledge that exists all comes from abstractions of experiences. Why bother calling it a posteriori when it is all there is?

The terms a priori ("from the earlier") and a posteriori ("from the later") are used in philosophy (epistemology) to distinguish two types of knowledge, justifications or arguments:

A priori knowledge or justification is independent of experience (for example "All bachelors are unmarried"). Galen Strawson wrote that an a priori argument is one in which "you can see that it is true just lying on your couch. You don't have to get up off your couch and go outside and examine the way things are in the physical world. You don't have to do any science.";[1] a posteriori knowledge or justification is dependent on experience or empirical evidence (for example "Some bachelors are very happy"). A posteriori justification makes reference to experience; but the issue concerns how one knows the proposition or claim in question—what justifies or grounds one's belief in it.