The antonyms for the phrase "didst one thing" can vary widely depending on context. If we consider the term more broadly as "taking action in a single direction," then some antonyms might include "stood still," "hesitated," "avoided," or "abstained." On the other hand, if we focus on the word "didst" specifically, we might consider antonyms like "failed," "refrained," or "ignored." Regardless of the specific word choices, the key idea behind antonyms for "didst one thing" is that they represent a lack of action or an opposite approach to the one taken.