Antonyms are words that have opposite meanings to each other. For the word "block," some of its antonyms include "clear," "open," "free," "unobstructed," and "accessible." These words imply movement, space, and the absence of barriers or obstacles. "Clear" suggests that there are no objects in the way, whereas "open" means that there is nothing blocking the path or view. "Free" implies complete freedom of movement, while "unobstructed" emphasizes the absence of anything that could hinder progress. Finally, "accessible" implies that there are no barriers in the way that would prevent someone from reaching something. All of these antonyms offer a sense of ease and flow, without any hindrances that could slow someone down.