Definition of "precocity"

I cannot learn that he gave in his youth, any evidence of that precocity which sometimes distinguishes uncommon genius.

1817 William Wirt, Sketches of the Life and Character of Patrick Henry, New York: M'elrath, Bangs & Co., 1834, Section I, pp. 23-4

By the side of many tall and bouncing young ladies in the establishment, Rebecca Sharp looked like a child. But she had the dismal precocity of poverty.

1847 January – 1848 July, William Makepeace Thackeray, chapter 2, in Vanity Fair […], London: Bradbury and Evans […], published 1848

It was as if his precocity of crookedness (and every vulgar villain is precocious) had for once deceived him, and the man he had sought to entrap as a simpleton had, through his very simplicity, ignominiously baffled him.

1924, Herman Melville, chapter 15, in Billy Budd‎, London: Constable & Co.

Anna Comnena, the Byzantine princess turned historian, sees our eleventh-century forebears in just this light, as appears in the mixture of horror with contempt which is her reaction to the mechanical ingenuity of the Crusaders' cross-bow, a Western novelty of her day which—with the characteristic precocity of lethal inventions—preceded by several centuries the invention of clockwork […]

1946, Arnold J. Toynbee, A Study of History, Abridgement of Volumes I-VI by D.C. Somervell, Oxford University Press, Chapter XII, p. 242

How can we explain the relative precocity in political studies that the Greeks demonstrated in contrast to the backwardness of other early peoples?

1964, William Anderson, Man's Quest for Knowledge: The Study and Teaching of Politics in Ancient Times‎, Minneapolis: University of Minnesota Press, Epilogue, p. 329

Short stature persists into adult life but puberty is usually normal, although sexual precocity has been seen […]

1999, Leonard Pinsky, Robert P. Erickson, R. Neil Schimke, chapter 15, in Genetic Disorders of Human Sexual Development, Oxford University Press, page 314