Definition of directed graph in English English dictionary
A graph in which the edges are ordered pairs, so that, if the edge (a, b) is in the graph, the edge (b, a) need not be in the graph and is distinct from (a, b) if it is
A directed graph (A,R) is a set of vertices A together with an incidence relation R: if aRb then there is an edge going from A to B.
A data structure that represents a set of strings and allows for a query operation that tests whether a given string belongs to the set in time proportional to its length (thus more efficient in some situations than a trie)