Jiggliest is the superlative form of jiggly, meaning something that is wobbly, shaky or unstable. The antonyms for the word jiggliest would be stable or firm, which means something that is fixed or steady. Other antonyms for jiggly would be solid, rigid or immovable, indicating things that are not flexible or prone to movement. Additionally, words like sturdy or robust would serve as antonyms for jiggliest, which describes something that is strong and substantial. In conclusion, the antonyms for jiggliest are stable, firm, solid, immovable, rigid, sturdy and robust, all indicating a strong or stationary object.