jump out of one's skin
To be badly frightened; be very much surprised.
The lightning struck so close to Bill that he almost jumped out of his skin.
jump pass
A pass (as in football or basketball) made by a player while jumping.
The Bruins scored when the quarterback tossed a jump pass to the left end.
jump the gun
beat the gun
To start before the starter's gun in a race.
The runners were called back because one of them jumped the gun.
To start before you should; start before anyone else.
The new students were not supposed to come before noon, but one boy jumped the gun and came to school at eight in the morning.
The students planned to say happy birthday to the principal when the teacher raised her hand, but Sarah jumped the gun and said it when he came into the room.
jump the track
To go off rails; go or run the wrong way.
The train jumped the track and there was a terrible accident.
The pulley of the clothesline jumped the track and Mother's washing fell down.
To change from one thought or idea to another without plan or reason; change the thought or idea you are talking about to something different.
Bob didn't finish his algebra homework because his mind kept jumping the track to think about the new girl in class.
jump through a hoop
To do whatever you are told to do; obey any order.
Bob would jump through a hoop for Mary.
jump to a conclusion
To decide too quickly or without thinking or finding the facts.
Jerry saw his dog limping on a bloody leg and jumped to the conclusion that it had been shot.
jumping-off place
A place so far away that it seems to be the end of the world.
Columbus' sailors were afraid they would arrive at the jumping-off place if they sailed farther west.
So you visited Little America? That sounds like the jumping-off place!
The starting place of a long, hard trip or of something difficult or dangerous.
The jumping-off place for the explorer's trip through the jungle was a little village.
kick over the traces
jump the traces
To break the rules; behave badly.
When their teacher was absent and they had a substitute, the children kicked over the traces.