Definition: make slack as by lessening tension or firmness
Main entry: slacken
Definition: become looser or slack
Usage: the rope slackened
Main entry: slack, slacken, slow, slow down, slow up
Definition: become slow or slower
Usage: Production slowed
Main entry: slack, slack up, slacken, relax
Definition: make less active or fast
Usage: He slackened his pace as he got tired; Don't relax your efforts now