definition of
[slacken]

[1] #1 slacken v. [slow, slow down, slow up, slack] become slow or slower; "Production slowed". wn

[2] #2 slacken v. [slack, slack up, relax] make less active or fast; "He slackened his pace as he got tired"; "Don't relax your efforts now". wn

[3] #3 slacken v. become looser or slack; "the rope slackened". wn

[4] #4 slacken v. [remit] make slack as by lessening tension or firmness. wn