drop-in

Meanings

1. Provided for short-term use.
2. Fit to substitute for some element in a complex system without changes to the existing infrastructure.
3. Allowing people to drop in; that is, to visit casually, without an appointment.
4. Of the pitch: prepared away from the ground or venue, and dropped into place only when a match is to be played.

1. One who casually drops in (visits unannounced or without appointment).
2. An informal event that does not require booking in advance.
3. A place that can be visited casually, without an appointment.
4. The act of dropping in; that is, taking a wave that another surfer is already riding.
5. A pitch that is prepared away from the ground or venue, and dropped into place only when a match is to be played.
6. A message or advertisement inserted into other material.