The antonyms for the word "more tightened" could be "loosened", "relaxed", "slackened" or "softened". These terms all indicate a decrease in pressure, tension, or firmness. The opposite of tightened is to make something less taut, firm or secure. In certain contexts, antonyms of "tightened" can also include "enlarged", "expanded" or "extended," which signify an increase in size, volume or scope. Understanding antonyms is critical in expressing ideas and positive communication. Choosing the right antonym can help clarify the message and ensure that the listener or reader receives the intended message.