popin
- Drop by unannounced
- Arrive unexpectedly
- Surprise at the door
- Call on unannounced
- Arrive without an invite
- Appear uninvited
- Visit without advance notice
- Visit on the go
- Swing by unannounced
- Show up unannounced
- Pay a quick visit
- Make an unannounced visit
- Make an impromptu visit
- Make an impromptu entrance
- Enter informally
- Appear by surprise