surface; externality

The quality of being exterior.

plural of exterior angle

(geometry) An angle formed between one side of a polygon and an extension of an adjacent side.

(calculus) A differential operator which acts on a differential k-form to yield a differential (k+1)-form, unless the k-form is a pseudoscalar, in which case it yields 0.

(algebra) A kind of product between vectors and/or multivectors which is associative, linear, and alternating.

plural of exterior product