(mathematics) the set of rigid motions that are also affine transformations.

Ordinary two- or three-dimensional space, characterised by an infinite extent along each dimension and a constant distance between any pair of parallel lines.

(historical) Any of certain algorithms first described in Euclid's Elements.

(mathematics) Two-dimensional Euclidean space.

A sociopolitical region in the west of Europe.

(computing, mathematics) A flash of insight that cracks a problem and paves the way to a solution.

plural of Eureka step

(biology, of a body of water) Being rich in nutrients and minerals and therefore having an excessive growth of algae and thus a diminished oxygen content to the detriment of other organisms.

(medicine) A eutrophic medicine.

In terms of, or by means of, eugenics.