(mathematics, uncountable) The branch of mathematics dealing with spatial relationships.

(mathematics, often qualified in combination, countable) A mathematical system that deals with spatial relationships and that is built on a particular set of axioms; a subbranch of geometry which deals with such a system or systems.

(countable) The observed or specified spatial attributes of an object, etc.

(algebraic geometry, countable) A mathematical object comprising representations of a space and of its spatial relationships.