Definition of "zigzag"

The entrance to this ancient place of devotion was under a very low round arch, ornamented by several courses of that zig-zag moulding, resembling shark's teeth, which appears so often in the more ancient Saxon churches.

1820, Walter Scott, chapter II, in Ivanhoe; a Romance. […], volume II, Edinburgh: […] Archibald Constable and Co.; London: Hurst, Robinson, and Co. […], page 20

His thoughts were fixed on one subject, and it was an effort to him to follow the zigzag remarks of his children—an effort which he did not make.

1855, Elizabeth Gaskell, chapter 6, in North and South‎, volume 2, London: Chapman & Hall, pages 78–79

There, by dint of looking closely about me, I found a rough zig-zag descending path notched out: which I followed.

1866 December 10, Charles Dickens, “No. 1 Branch Line. The Signal-Man.”, in Charles Dickens, editor, Mugby Junction. The Extra Christmas Number of All the Year Round, volume XVI, London: Published at No. 26, Wellington Street; and by Messrs. Chapman and Hall, […], page 21, column 1

Then he addressed a keen-sighted, remembering gaze to the rim-wall above. It was serrated, and between two spears of rock, directly in line with his position, showed a zigzag crack that at night would let through the gleam of sky.

1912 January, Zane Grey, “Surprise Valley”, in Riders of the Purple Sage […], New York, N.Y., London: Harper & Brothers Publishers, page 102

At the base this vent was dark, cool, and smelled of dry, musty dust. It zigzagged so that he could not see ahead more than a few yards at a time.

1912 January, Zane Grey, “Surprise Valley”, in Riders of the Purple Sage […], New York, N.Y., London: Harper & Brothers Publishers, page 98

If the first two novels created a new genre — Peakean fantasy — then this third volume zigzags between several: the Bildungsroman, science fiction, social satire, morality tale and dystopian prophecy.

2002, Malcolm Yorke, Mervyn Peake: My Eyes Mint Gold: A Life, page 298