The word "stymy" can mean to block or hinder progress. Some synonyms for this word include obstruct, impede, hamper, hinder, and thwart. These words all suggest something in the way of progress, whether physical or metaphorical. Other synonyms for stymy include frustrate, constrain, deter, and curb, which suggests a limiting factor but not necessarily an insurmountable one. Additionally, words like confound, perplex, and puzzle suggest complicating factors that can cause confusion or delay. Whatever the specific synonym used, each implies a challenge or obstacle to overcome in order to succeed.