Definition of "drop in" in English

Verb

1. Used other than figuratively or idiomatically: see drop,‎ in.

   • The keys were dropped in the fishbowl.

2. To arrive casually and unannounced, with little or no warning; also, to visit without an appointment.

   • I was in the garden covered with mud when my grandmother dropped in for a visit.

3. To paddle into and take off on a wave another surfer is already riding.

4. To fall in; to cave in.

5. To install components, particularly car engines.

   • We dropped in all-new parts in the sports car.

Noun

1. Alternative spelling of drop-in.