slack 1 
(slăk)
(slăk)adj. slack·er, slack·est
1. Not tense or taut; loose: a slack rope; slack muscles. See Synonyms at loose.
2.
a. Lacking in activity; not busy: a slack season for the travel business.
b. Moving slowly; sluggish: a slack pace.
3. Lacking in diligence or due care or concern; negligent: a slack worker. See Synonyms at negligent.
4. Flowing or blowing with little speed: a slack current; slack winds.
5. Linguistics Pronounced with the muscles of the tongue and jaw relatively relaxed; lax.
v. slacked, slack·ing, slacks
v.tr.
1.
a. To make looser or less taut: slacked the sail.
b. To make slower: slacked our pace.
2. To be careless or remiss in doing: slack one's duty.
3. To slake (lime).
v.intr.
1. To be or become slack.
2. To be inactive or avoid work: slacked around the house all day.
n.
1. A loose part, as of a rope or sail: hauled in the slack.
2. A period of little activity; a lull: a slack in business.
3.
a. A cessation of movement in a current of air or water.
b. An area of still water.
4. Unused capacity: still some slack in the economy.
5. slacks Casual pants that are not part of a suit.
adv.
Phrasal Verb: In a slack manner: a banner hanging slack.
slack off
Idiom: 1. To decrease in activity or intensity.
2. To work less intensely than is required or expected: slacked off at work and started surfing the internet.
cut/give (someone) some slack
Slang To make an allowance for (someone), as in allowing more time to finish something.
[Middle English slak, from Old English slæc; see slēg- in the Appendix of Indo-European roots.]
slackly adv.
slackness n.