different between slackening vs unremitting

English

slackening

slackening (plural slackenings)

The act by which something slackens; loss of speed, tautness, etc.
- 1861, United States. War Dept, U.S. Infantry Tactics (page 124)
  If the following guide lose his distance from the one leading (which can only happen by his own fault), he will correct himself by slightly lengthening or shortening a few steps, in order that there may not be sudden quickenings or slackenings in the march of his platoon.

1728, un- +? remitting, from remit, from Latin [Term?], in now rare sense of “diminish, abate”. Not from (non-existent) *unremit.

unremitting (comparative more unremitting, superlative most unremitting)

incessant; never slackening
- 1961: J. A. Philip. Mimesis in the Sophistês of Plato. In: Proceedings and Transactions of the American Philological Association 92. p. 467.
  We can achieve this god?likeness only by unremitting and strenuous effort of the intellect.

Send