(a) a point on a graph or in space having integral coordinates; (b) any of the points of which a lattice, esp. a crystal lattice, is composed.

Mathematics. A unique node or vertex of a graph from which every other node can be reached. Also root node.

A point of a network, tree diagram, or graph (graph, n.1 1) where a line meets another line or terminates. Also called vertex.

Mathematics. A junction of two or more lines in a network or graph (graph, n.1 1); = node, n. 9a.