Uncongested is a word used to describe an area, road or space that is free from traffic or any kind of obstruction. The antonyms of the word uncongested are congested, blocked, packed, choked, and gridlocked. Congested is an antonym for uncongested as it means crowded, blocked or overcrowded. Blocked refers to a pathway being blocked or obstructed in some way. Packed suggests that a certain space is tightly filled with people or objects. Choked refers to a situation where something is blocking air, water, or other essential things. Finally, gridlocked signifies a situation where a place or area is completely blocked because of traffic.