The antonyms for the phrase "part parcel" include "separate," "independent," "unrelated," and "disconnected." When something is part and parcel, it means it's an essential and integral part of something else. For instance, feedback is part and parcel of the learning process. However, when these expressions' antonyms are applied, it simply means that there's no connection between two or more things. For instance, a random stranger's story at a party may be disconnected or unrelated to the topic of the conversation. The antonyms can help in improving communication and avoiding confusion by specifying the absence of any connections.