The property of representations of a part of the world that captures that part as being a certain way; meaning.

Referred to as 'aspectual shape' by Searle (1992). For Frege the sense of an expression is the manner in which we determine its reference, and he tells us a great deal about the kind of reference possessed by expressions of different types, thereby specifying the form that the senses of such expressions must take. The sense of an expression is also called the 'mode of presentation' of the referent.

Evans (1985) claims "a theory of meaning for a language must give the senses of expressions, we are not to think of the theory of meaning as a separate tier, additional to and independent of the theory of reference. If sense is a way of thinking of reference, we should not expect to be given the sense of an expression save in the course of being given the reference of that expression."
Chris Eliasmith