bottom drop out
bottom fall out
To fall below an earlier lowest price.
The bottom dropped out of the price of peaches.
To lose all cheerful qualities; become very unhappy, cheerless, or unpleasant.
The bottom dropped out of the day for John when he saw his report card.
The bottom fell out for us when the same ended with our team on the two yard line and six points behind.
break someone's fall
Смягчать падение, удар.
When the little boy fell out of the window, the bushes broke his fall.
Когда маленький мальчик выпали из окна, кусты смягчили удар.
To take (someone or something) part of the way you are going.
Joe asked Mrs. Jones to drop him off at the library on her way downtown.
I don’t mind dropping you off at the store on my way to work.
To fall asleep.
Jimmy was thinking of his birthday party as he dropped off to sleep.
My mother dropped off during the boring television show; her head was nodding up and down.
The patient dropped off in his sleep.
To become less. When the quality, degree, or frequency of something decreases, it falls off.
Business picked up in the stores during December, but dropped off again after Christmas.
Sales of fountain pens fell off after the ballpoint pen was invented.
The quality of his work has fallen off as he has gotten older.
Business has been dropping off rapidly recently, but fortunately it hasn’t been falling off as quickly as for our competitors.
fall all over
fall all over someone
To show too much love or thanks toward (someone).
She must love him. Every time you see them, she's falling all over him.
When Bob found the lady's ring and returned it, she fell all over him.
fall asleep at the switch
To fail to perform an expected task; be remiss in one's duty.
The two airplanes wouldn't have collided, if the control tower operator hadn't fallen asleep at the switch.
The dean promised our department $250,000 but the foundation never sent the money because someone in the dean's office fell asleep at the switch.
To decline; diminish.
I was shocked to see how haggard Alan looked; he seems to be falling away to a shadow.
fall back on
fall back upon
To retreat to.
The enemy made a strong attack, and the soldiers fell back on the fort.
To go for help to; turn to in time of need.
When the big bills for Mother's hospital care came, Joe was glad he had money in the bank to fall back on.
If Mr. Jones can't find a job as a teacher, he can fall back on his skill as a printer.
To move back; go back. Usually used with a group as subject.
The army fell back before their stubborn enemies.
The crowd around the hurt boy fell back when someone shouted "Give him air!"