collision
noun [ C or U ]
uk/kəˈlɪʒən/ us INSURANCE
an accident in which two vehicles hit each other:
Injuries from rear-end collisions were down, which could mean more than $45 million saved on accident damage per year.
collision damage
be on a collision course
if two or more people or groups are on a collision course, they are doing or saying things which will cause a disagreement or problems between them:
The House and the Senate are again on a collision course over transportation.