Definition of: slacken

(slak′ən) v.i.
1. To become slack, as business; diminish; retard.
2. To become less tense or tight; loosen.
3. To become slow or less intense.
—v.t.
4. To be or become negligent of or remiss in; to avoid, as duty, especially a military duty; shirk.
5. To make slack.