"Piece of the pie" is a colloquial expression used to refer to a share or a portion of something. Antonyms of this phrase may include: exclusion, deprivation, and scarcity. Whereas a piece of the pie implies inclusion and abundance, exclusion suggests the opposite. Deprivation is also an antonym because it implies a lack of something essential or desirable, which is quite the opposite of having a share. Scarcity, on the other hand, refers to a shortage of something, which would mean that there isn't enough pie to go around. Thus, these antonyms convey themes of inequality, inadequacy, and shortage, which are the polar opposites of the idea of having a fair share or an adequate portion.