"Un-acquainted" is a term that implies a lack of familiarity with someone or something. Its antonyms, on the other hand, are words that describe a state of knowing or familiarity. Some of the possible antonyms for "un-acquainted" include acquainted, familiar, cognizant, aware, knowledgeable, and well-informed. These terms indicate a level of understanding, recognition, or awareness of a person, place, or thing. Being acquainted with someone or something implies having some knowledge or connection with them, while being familiar speaks of a deeper level of understanding and comfort. Cognizant and aware mean being attentive and mindful of something, while knowledgeable and well-informed indicate expertise or a high level of knowledge about a particular subject or area.