[drop-er-in] 
[drop-in] | 1. | Informal. Also, dropper-in. a person who or thing that pays an unexpected or uninvited visit: a feeder for squirrels, raccoons, and other drop-ins. |
| 2. | Informal. a social gathering at which the guests are not expected to stay long: Be sure to stop by our house for a glass of eggnog at our Christmas drop-in. |
| 3. | provided for short-term patronage: a drop-in shelter for the homeless. |
| 4. | requiring only insertion to be ready for use: a drop-in film cartridge. |
