The term "is cognizant" suggests being aware, knowledgeable, or mindful of a particular subject or situation. Its antonyms can vary depending on the context, but some common words that represent its opposite meaning are oblivious, ignorant, unaware, unfamiliar, and uninformed. For instance, if someone is not cognizant of a change in a plan, they may be oblivious or unaware of its occurrence. Similarly, if someone is not cognizant of a particular topic, they may be considered ignorant or uninformed about it. Knowing the antonyms of "is cognizant" can help improve communication and understanding in various settings.