- jump the track
- jump the track1. Lit. [for something] to fall or jump off the rails or guides. (Usually said about a train.) •
The train jumped the track, causing many injuries to the passengers.
•The engine jumped the track, but the other cars stayed on.
2. Fig. to change suddenly from one thing, thought, plan, or activity to another. •The entire project jumped the track, and we finally had to give up.
•John's mind jumped the track while he was in the play, and he forgot his lines.
* * *{v. phr.} 1. 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./ 2. {informal} 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./ Compare: OFF THE TRACK.
Dictionary of American idioms. 2013.