1. anticipating the second half of a two-part unpleasant action to take place; to wait for the inevitable next step or the final conclusion

1. After my forgetful sister told me that she had taken my camera cell phone on the class trip, I waited for the other shoe to drop. I expected her to say that she had lost it.

2. He just opened his mail and moaned. Now, I’m waiting for the other shoe to drop when he finds the subpoena.