Available Definitions:
1) n. - Small coal; also, coal dust; culm.
2) n. - A valley, or small, shallow dell.
3) superl. - Lax; not tense; not hard drawn; not firmly extended; as, a slack rope.
4) superl. - Weak; not holding fast; as, a slack hand.
5) superl. - Remiss; backward; not using due diligence or care; not earnest or eager; as, slack in duty or service.
6) superl. - Not violent, rapid, or pressing; slow; moderate; easy; as, business is slack.
7) adv. - Slackly; as, slack dried hops.
8) n. - The part of anything that hangs loose, having no strain upon it; as, the slack of a rope or of a sail.
9) a. - Alt. of Slacken
10) v. t. - Alt. of Slacken