Adjacent

Adjacent is an adjective meaning contiguous, adjoining or abutting. It is commonly used in scientific, specifically mathematical contexts.

In graph theory, two vertices (or nodes) in a graph are called adjacent if they are linked by an edge. Adjacency of vertices in a graph is represented by the adjacency matrix.

In plane geometry, two sides of a polygon are called adjacent if they meet in an angle.

In trigonometry, the adjacent side of an angle of a right-angled triangle is the cathetus next to this angle.