This happens when a dating couple tries the long-distance relationship thing when they go off to university or college in September. Typically, when Thanksgiving rolls around and everyone goes home for the holiday, someone gets dumped. Hence the turkey drop. 

当一对高中情侣九月份离家去上大学时，他们不得不进行异地恋。当第一个感恩节到来时，大家都回家过节，这时候总有些人会被甩掉。这就叫“放弃火鸡”。

Example:

I hope Bob and I make it past the turkey drop.

我希望鲍勃和我能挺过“放弃火鸡”的考验。