The phrase "was apprised of" means to be informed or notified of something. Its antonyms could include words like unaware, uninformed, oblivious, and ignorant. These terms suggest that a person hasn't been made aware of particular information, either intentionally or unintentionally. Other possible antonyms for "was apprised of" include "in the dark" and "not clued in," which carry similar connotations of ignorance or lack of knowledge. Conversely, synonyms for "apprised of" might include words like informed, briefed, advised, or alerted, which suggest that someone has been given access to pertinent information.