n. 1. a drawing showing the relationship between certain sets of quantities or numbers by means of a series of lines, points, etc., plotted with respect to a set of coordinate axes. See, for example, bar graph. 2. a drawing showing a functional relationship between two or more variables by means of a curve, surface, etc. containing all and only those points the coordinates of which satisfy the relation. For example, this graph shows part of the graph of y = x sin(x + 1) - 1, since the coordinates of every point that lies on the curve satisfy this relation.
3a. the set of points 〈x, y〉 where y = f(x), as contrasted with the function f.
b. the set of points 〈x, y〉 where y ∈ f(x) as contrasted with the set-valued function f. 4. (Graph theory) a set of points (vertices) and line segments (edges) that connect some of these vertices, used both in the study of topology and in combinatorics and the construction of combinatorial algorithms. See also tree.