Unaccustom is a word that means not being familiar or accustomed to something. When we encounter something new or unfamiliar, we may feel unaccustomed to it. Synonyms for unaccustom include disaccustom, unaccustomed, unfamiliar, untried, and new. Disaccustom refers to getting rid of one's habitual practice, while unaccustomed describes a lack of familiarity or experience. The term unfamiliar denotes something strange, unknown, or not recognized. Untried refers to something that has not been tested, proven, or experimented with. Lastly, new is a synonym for unaccustom because it implies something that has never been experienced or encountered before.