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 in English since the Middle English period. The combination expresses negation of an action that would ordinarily be solicited, invited, or commanded. The everyday parallel is uninvited, but unbidden often carries a stronger tone of involuntary emergence.

Common uses describe unbidden guests or unbidden thoughts. For example, a visitor who arrives unbidden may be unwelcome or a surprise; unbidden memories or instincts are memories or impulses that surface without intention or consent. In prose, unbidden can heighten drama by highlighting the abrupt arrival of something beyond the speaker's control.

Related terms include uninvited and unsolicited; difference lies in connotation: unbidden emphasizes inner intrusion or inevitability, while uninvited stresses lack of invitation. The word remains primarily literary or formal and is less frequent in everyday informal speech.