Unnotified is a term used to describe something that has not been communicated or shared with others in advance. There are various synonyms for unnotified that could be used in different contexts. Some of the synonyms for unnotified include unannounced, unexpected, unheralded, sudden, and impromptu. These words are often used to describe events, meetings, and visits that happen without prior notice. Additionally, there are other synonyms that may be used to describe unnotified in different situations such as unheard, unobserved, unnoticed, and unseens. These words may be used to describe situations or occurrences that happened without being perceived or noticed by anyone.