- connecting two nonadjacent angles or vertices of a polygon or polyhedron, as a straight line.
- extending from one edge of a solid figure to an opposite edge, as a plane.
Origin of diagonal
Examples from the Web for diagonally
Place these Nine in a Square of three, they will directly and diagonally make 18.The History of the Devil|Daniel Defoe
On the opposite corner, diagonally, have an imitation stump with hatchet sticking in the wood.Dinners and Luncheons|Paul Pierce
The red letters of "Votes for Women" ran around her diagonally like the stripes of a barber-pole.Affinities and Other Stories|Mary Roberts Rinehard
Diagonally across it, many yards away, ran one of the stone fences of the region, a long dike of loosely piled and rounded rock.The Long Roll|Mary Johnston
Diagonally across from your house, in the corner house; in my window, in a cage, is a canary.Delusion and Dream|Wilhelm Jensen
British Dictionary definitions for diagonally
Word Origin for diagonal
Word Origin and History for diagonally
1540s (implied in diagonally), from Middle French diagonal, from Latin diagonalis, from diagonus "slanting line," from Greek diagonios "from angle to angle," from dia- "across" (see dia-) + gonia "angle," related to gony "knee" (see knee (n.)). As a noun, from 1570s.