Definition of on a collision course in English:

on (a) collision course

1Going in a direction that will lead to a collision with another moving object or person.
More example sentences
  • At Manchester Airport in February a MyTravel Airways plane and a Ryanair aircraft were on collision course before take-off and disaster was averted only by the fast reactions of one of the pilots.
  • This move by Falkirk could put the SPL on collision course with the SFA, leading to the long-predicted battle for the control of Scottish football.
  • They have studiously avoided playing each other and, on the rare occasions when they have found themselves on collision course, they have side-stepped the issue, claiming injury.
1.1Adopting an approach that is certain to lead to conflict with another person or group: the strikers are on a collision course with the government
See parent entry: collision