The antonyms of the term "sate up" are numerous and varied in usage. The phrase suggests a feeling of fullness, contentment, or complacency, so antonyms would most likely denote the opposite feelings or states. Some possibilities include "starved," "depleted," "unfulfilled," or "discontented." Other potential antonyms could be "dissatisfied," "hollow," "unsatisfied," or "lacking." Ultimately, the best antonym would depend on the context in which the term "sate up" is being used. Knowing and using appropriate antonyms can add depth and nuance to everyday communication and writing.