The phrase "didst the sly" can be translated to mean "did in a cunning or sly manner." Some synonyms for this phrase include acted surreptitiously, behaved deceptively, performed sneakily, and operated furtively. Other related words to consider may include schemes, plans, and tricks. Ultimately, this phrase describes a behavior or action that is meant to be hidden from others or executed with a level of stealth. Synonyms for "didst the sly" can help to convey a sense of how the action was taken and what intent may have been behind it.