The Collaborative International Dictionary
Diminishment \Di*min"ish*ment\, n.
Diminution. [R.]
--Cheke.
Wiktionary
n. The act of diminishing; reducing in size, quantity, or quality.
Wikipedia
Diminishment is the legal process by which the United States Congress can reduce the size of an Indian reservation.
In 1984, the United States Supreme Court held in Solem v. Bartlett, 465 U.S. 463 (1984), that "only Congress may diminish the boundaries of an Indian reservation, and its intent to do so must be clear." This was noted in the Court's 2016 case Nebraska v. Parker, 577 U.S. ___ (2016), in which the Court held that an 1882 Act passed by Congress did not diminish the Omaha Reservation.
The Solem case established a "diminishment doctrine" that U.S. courts could use when evaluating whether diminishment had taken place.
In the 1994 case Hagen v. Utah, 510 U.S. 399 (1994), the Supreme Court held that Congress's 1902 Act had diminished the Uintah Reservation. The Court applied its doctrine established in the Solem case.
Usage examples of "diminishment".
Even in his diminishment the power of Melkor is beyond our calculation.
The two rather self-centered and somewhat irrational archimages, intent on and vastly enamored of their private war—though they were undoubtedly the cunningest and wisest sorcerers ever to exist in the World of Nehwon—were entirely adamant against the very sound four arguments Fafhrd and the Gray Mouser advanced in their self-defense: one, that they had stuck to the magician-set rules by first making certain to get the Mask of Death (or as much as they could of it) out of the Shadowland at whatever personal cost to themselves and diminishment of their self-respect.
The two rather self-centered and somewhat irrational archimages, intent on and vastly enamored of their private war -- though they were undoubtedly the cunningest and wisest sorcerers ever to exist in the World of Nehwon -- were entirely adamant against the very sound four arguments Fafhrd and the Gray Mouser advanced in their self-defense: one, that they had stuck to the magician-set rules by first making certain to get the Mask of Death (or as much as they could of it) out of the Shadowland at whatever personal cost to themselves and diminishment of their self-respect.
It was not Raghallach they had taken, but the Sidhe Nuallan-Nuallan they dragged struggling away in the other direction, past the door with its wards, its diminishments of Sidhe power.
But as I was at it I should add, she'd add, the psychological cost of parentage, to ourselves individually and to the marital relationship: fatigue, loss of spontaneity, diminishment of ardor, general heaviness -- a kind of accelerated aging, the joint effect of passing years, increased responsibility, and accumulated familiarity -- never altogether compensated for by deeper intimacy.