(archaic, Scotland) A loud quarrelsome fight.

Synonym of Shetland sheepdog

plural of toy collie

plural of rough collie

(veterinary medicine) A congenital, inherited, bilateral eye disease of dogs characterized by an underdeveloped choroid.

An instance of colliding. / (physics) Any event in which two or more bodies exert forces on each other in a relatively short time. In a collision, physical contact of two bodies is not necessary.

(chemistry) Any theory that relates collisions among particles to reaction rate; reaction rate depends on such factors as concentration, surface area, temperature, stirring, and the presence of either a catalyst or an inhibitor.

(physics) A high-energy nuclear reaction in which two nuclei overlap and exchange energy and nucleons

(transport) A collision where the front ends of two vehicles (such as ships, trains, cars, planes, etc.) hit each other, as opposed to a side-collision or rear-end collision.

plural of head-on collision