A dog of either of two different breeds (the English springer spaniel and the Welsh springer spaniel).

An opening made by the pupil in the eye.

A transparent form of calcite, used to demonstrate the polarisation of light.

(control engineering) A mathematical model of a physical system as a set of input, output and state variables related by first-order differential equations.

A manifold or topological space X on which G acts by symmetry in a transitive way.

The range of parameter values between two successive knots in a spline.

The process, made possible by technological innovations in transportation and communication, by which distant places are brought closer together in terms of the time taken to travel (or send messages) between them.

A breed of toy dog originating from England.

A former colony of Spain in Central Africa, now called Equatorial Guinea.

Alternative letter-case form of spaghetti western