Most blocked is a term used to refer to the condition where something is impeded or obstructed. Antonyms for most blocked would, therefore, be words that describe a state of being unrestricted, free, or unobstructed. Some suitable antonyms may include terms like open, free-flowing, unimpeded, clear, or unrestricted. In essence, these words describe a state or condition where there are no hindrances or inhibitions that would prevent the natural flow or movement of something. For instance, an open road would be an antonym of a blocked road, or a free-flowing river would be an antonym of a dammed-up river.