slack

noun

1.
dust consisting of a mixture of small coal fragments and coal dust and dirt that sifts out when coal is passed over a sieve
Derived from:
slack
2.
a noticeable deterioration in performance or quality
drop-off falling off falloff slump
Derived from:
slack
3.
a stretch of water without current or movement
slack water
Derived from:
slack
4.
a soft wet area of low-lying land that sinks underfoot
gote mizzy quob slough mire morass quag quagmire
5.
the quality of being loose (not taut)
slackness
Derived from:
slack slack
6.
a cord or rope or cable that is hanging loosely
Derived from:
slack slack