Definition of "slack" []

• Moving slowly; sluggish: a slack pace. (adjective)
• Lacking in activity; not busy: a slack season for the travel business. (adjective)
• Not tense or taut; loose: a slack rope; slack muscles. See Synonyms at loose. (adjective)
• Lacking firmness; flaccid: a slack grip. (adjective)
• Lacking in diligence or due care or concern; negligent: a slack worker. See Synonyms at negligent. (adjective)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "His eyes were dark and blank, his expression slack."
• "The forenoon being what he called his slack time he found the earlier part of it most profitably used for sleep."
• "About ten minutes or so, those tugs, five tugs in all, were pulling with all their might to try and get this old gray lady off of Pier 86 and finally, as we stood on the flight deck, there was movement, very slow at first, and then she just took off and she was traveling faster than I think they expected and we ended up just sitting off of the Bayone wet dock for about three hours waiting for what they call slack to decrease or lower tide to come in so the ship could be controlled better and brought right into this dock that we are obviously just now moving into."