(philosophy) A specific form of rationality focusing on coming to accurate beliefs about the world based on available evidence.

The process of economic agents aiming to maximise their objectives, by ensuring the marginal benefit of an action is equal to its marginal cost.

Synonym of ration stamp

(social sciences, economics, political science, sociology) A theory that argues individual decisions are based on that individual's understanding of the costs and benefits of a given action, shaped throughout the assumptions of self-interest and rational actors.

(algebra) A theorem which states a constraint on rational solutions of a polynomial equation with integer coefficients.

(historical) Practical, comfortable clothing proposed in the Victorian era as an alternative to the fashions of that time.