Drop by the wayside

To give up or fail before the finish of something.Many runners dropped by the wayside during the marathon.

Drop a hint

To casually make a hint or suggestion about something.The clerk dropped a hint that he wanted to transfer to a new department.

Drop a bombshell

To announce some shocking news.The government dropped a bombshell when they announced that they were going to close the hospital.

Driving force behind (someone or something)

The motivating force behind someone or something.The potato farmers were the driving force behind the efforts to get people to eat more potatoes.

Drive up to (someone or something)

To approach someone or something.The car drove up to the bank.

Drive up (a price)

To make the price of something increase.The cold weather is driving up the price of heating oil.

Drive (something) home / drive home (something)

To make something clearly understood.The high price of gasoline drove home the necessity of driving less.

Drive (someone) up a wall

To irritate or annoy someone greatly.My neighbor's constant complaining is driving me up a wall.

Drive at (something)

To intend or mean to say something.I do not know what the man was driving at in his speech.

Drive a hard bargain

To conclude a bargain without making any concessions.Although the man drives a hard bargain, I like doing business with him.