collision

(noun) (physics) a brief event in which two or more bodies come together. Synonyms: hit. Example: "The collision of the particles resulted in an exchange of energy and a change of direction."

(noun) an accident resulting from violent impact of a moving object. Examples: "Three passengers were killed in the collision." "The collision of the two ships resulted in a serious oil spill."

(noun) a conflict of opposed ideas or attitudes or goals. Example: "A collision of interests."