Other forms: collisions
A collision is a crash between two moving things. Cars, ships, particles, or two people rounding the same corner.
The word requires movement on at least one side, and technically both. Police and insurers prefer it to accident, because accident implies nobody was at fault. Physics uses it precisely for particles. There is a strong figurative use, since a collision of interests or a collision course describes two things heading for an inevitable clash. The verb is collide, which takes with.
A collision is a striking together. Latin collīdō joins con, together, to laedō, to strike or to hurt, so the word carries the injury as well as the impact.
Latin
collīsiō — clash, concussion, collision
Middle French
collision
English, today
collision
Built from
From Middle French collision, from Latin collīsiō (“clash, concussion, collision”) (whence -ion), from collīsus (“clashed together, conflicted, contended”), past participle of collīdō (“to clash, strike, dash, beat, or press together”) (whence collide), from con- + laedō (whence col-).
Etymology from Wiktionary, CC BY-SA