collision course—
1. a course, as of moving vehicles, that will end in a collision if left unchanged:
- Because of the density of the fog, the deck officers did not realize that the ships were now on a collision course.
2. confrontation between opposing groups, etc. that may end in conflict:
- All attempts at diplomacy have broken down and the two states now appear to be on a collision course.
crash course—a short intensive course in which one is taught the most important facts and skills:
- Well, the powers that be stipulate that all teachers be computer literate. So I took a crash course in computers…