Noah Webster
Slackness
SLACK'NESS, noun
1. Looseness; the state opposite to tension; not tightness or rigidness; as the slackness of a cord or rope.
2. Remissness; negligence; inattention; as the slackness of men in business or duty; slackness in the performance of engagements.
3. Slowness; tardiness; want of tendency; as the slackness of flesh to heal.
4. Weakness; not intenseness.