Trustinesses, a barely used word in the English language, refers to the quality of being trustworthy or reliable. Its antonyms are words that convey the opposite meaning. One of the antonyms can be "unreliability," which refers to the inability to deliver on promises or meet expectations. Another antonym could be "dishonesty," which denotes a lack of integrity or adherence to ethical standards. "Deceitfulness" could be another antonym, which directly refers to the act of concealing the truth or misleading people. Alternatively, "mistrust" is an antonym that connotes suspicion or a lack of belief in someone or something. Overall, the antonyms of trustinesses all convey a sense of doubt or uncertainty towards an individual or a situation.