1900, Charles W. Chesnutt, The House Behind the Cedars, Chapter I,During this interlude, Warwick, though he had slackened his pace measurably, had so nearly closed the gap between himself and them as to hear the old woman say, with the dulcet negro intonation:...
1908, Kenneth Grahame, He seemed tired, and the Rat let him rest unquestioned, understanding something of what was in his thoughts; knowing, too, the value all animals attach at times to mere silent companionship, when the weary muscles slacken and the mind marks time.
1986, Mari Sandoz, The Horsecatcher‎Elk slackened the rope so he could walk farther away, and together they went awkwardly up the trail toward the grassy little flat...
To deprive of cohesion by combining chemically with water; to slake.to slack lime
