Definition of "overpopulation"

I hope for another end, though not, indeed, from any of the three remedies for over-population commonly suggested by economists. These three are, in brief—Colonization; Bringing in of waste lands; or Discouragement of Marriage.

1860 August–December, John Ruskin, “Essay I. The Roots of Honour.”, in “Unto This Last:” Four Essays on the First Principles of Political Economy, London: Smith, Elder and Co., […], published 1862, page 162

Over the whole extent of the South Seas, from one tropic to another, we find traces of a bygone state of over-population, when the resources of even a tropical soil were taxed, and even the improvident Polynesian trembled for the future.

1891 February–December, Robert Louis Stevenson, “Depopulation”, in In the South Seas […], New York, N.Y.: Charles Scribner’s Sons, published 1896, part I (The Marquesas), page 37