unbidden
Unbidden is an adjective describing something that is not invited, requested, or expected. It is often used for people who arrive without an invitation, but it is also applied to thoughts, memories, or feelings that occur without deliberate initiation. In literary and formal writing, unbidden conveys a sense of intrusion or spontaneity, depending on context.
Originating from un- plus bidden, the past participle of bid (to invite or command), unbidden has existed
Common uses describe unbidden guests or unbidden thoughts. For example, a visitor who arrives unbidden may
Related terms include uninvited and unsolicited; difference lies in connotation: unbidden emphasizes inner intrusion or inevitability,