The Rice University Neologisms Database

[acronym for "piece of shit"]; Something that is bad, unpleasant, or objectionable This term allows one to concisely describe something is a negative way with just one syllable. This term also allows one to publicly curse without saying something inappropriate. This is the case because most people will not understand what the term "pos" means. They probably think that is a neologistic clipping of the word "possible" rather than think that is an acronym. Their ignorance probably also stems from the fact that the term "piece of shit" is chiefly a noun, and thus most people would not think to associate it with the word "pos," since "pos" is an adjective. See Notes. I believe that the word may have undergone the process of zero derivation and become an adjective rather than a noun. By using zero derivation to make "pos" an adjective, the speaker further obfuscated the meaning of "pos," as mentioned above; perhaps he did this in order to hide its meaning from the general public, since it is a vulgar term. The word might also have undergone zero derivation because many nouns that are preceded by the word "so" have become adjectives through this process (i.e. the phrase "That is so money," which means "That is so awesome."). I note that this process of zero derivation would not be real zero derivation as we have defined it, since the term "pos" does not exist as noun. Furthermore, the term "pos" might have come from the adjectival use of "piece-of-shit" as in the Adam Sandler song "Piece-of-shit car." Since I have not heard the phrase "piece-of-shit" used adjectivally in any other context other than in this song, and since this song is over a decade old, I doubt that "piece-of-shit" still circulates in conversation as an adjective. If it is a neologism that just enjoyed one-time or very infrequent usage, and "piece of shit" is thus not an adjective, then zero derivation must have occurred. However, if "piece of shit" is an adjective in my friend's active vocabulary, then perhaps "pos" did not undergo zero derivation.