Dictionary definition · slack
noun
- dust consisting of a mixture of small coal fragments and coal dust and dirt that sifts out when coal is passed over a sieve
- a noticeable deterioration in performance or quality"the team went into a slump"
- a stretch of water without current or movement"suddenly they were in a slack and the water was motionless"
- a soft wet area of low-lying land that sinks underfoot
- the quality of being loose (not taut)"he hadn't counted on the slackness of the rope"
verb
- avoid responsibilities and work, be idle
- be inattentive to, or neglect"He slacks his attention"
- release tension on"slack the rope"
- make less active or fast"He slackened his pace as he got tired"
adjective
- not tense or taut"the old man's skin hung loose and grey"
- flowing with little speed as e.g. at the turning of the tide"slack water"
- lacking in rigor or strictness"such lax and slipshod ways are no longer acceptable"
Source: Open English WordNet (CC BY 4.0).