The word "in firmnesses" refers to a lack of strength, stability or resoluteness. Antonyms for this word would therefore include terms indicating firmness, strength, steadfastness and decisiveness. Examples of antonyms for "in firmnesses" could include terms like resolved, determined, unwavering, strong, stable, certain, resolute, firm, steady and committed. These words all suggest a sense of unwavering determination, steadfastness and strength in character or conviction. Using antonyms for "in firmnesses" can help to convey a sense of strength or decisiveness in communication, and can be particularly useful in persuasive writing or assertive conversations.