Definition of "plenitude"

The idea that the love of Philimore had abated, when hers for him seemed in its plenitude, was a most severe aggravation of her misfortune.

1838, [Letitia Elizabeth] Landon (indicated as editor), chapter XII, in Duty and Inclination: […], volume III, London: Henry Colburn, […], page 152

Louis ignored him, recalling the parlements to the plenitude of their powers on 23 September.

2002, Colin Jones, The Great Nation, Penguin, published 2003, page 393

Mankind's old greatness was created in scarcity. But what may we expect from plenitude?

1976 September, Saul Bellow, Humboldt’s Gift, New York, N.Y.: Avon Books, page 156