slack in WordNet English dictionary

1. become less in amount or intensity
   "The storm abated"; "The rain let up after a few hours"
   abate  let up  slack off  slack  die away 
   
2. make less active or intense
   slake  abate  slack 
   
3. make less active or fast
   "He slackened his pace as he got tired"; "Don't relax your efforts now"
   slack  slacken  slack up  relax 
   
4. release tension on
   "slack the rope"
   slack 
   
5. become slow or slower
   "Production slowed"
   slow  slow down  slow up  slack  slacken 
   
6. cause to heat and crumble by treatment with water
   "slack lime"
   slack  slake 
   
7. be inattentive to, or neglect
   "He slacks his attention"
   slack 
   
8. avoid responsibilities and work, be idle
   slack 
   

1. a noticeable deterioration in performance or quality
   "the team went into a slump"; "a gradual slack in output"; "a drop-off in attendance"; "a falloff in quality"
   slump  slack  drop-off  falloff  falling off 
   
2. a soft wet area of low-lying land that sinks underfoot
   mire  quagmire  quag  morass  slack 
   
3. a cord or rope or cable that is hanging loosely
   "he took up the slack"
   slack 
   
4. the quality of being loose (not taut)
   "he hadn't counted on the slackness of the rope"
   slack  slackness 
   
5. a stretch of water without current or movement
   "suddenly they were in a slack and the water was motionless"
   slack  slack water 
   
6. dust consisting of a mixture of small coal fragments and coal dust and dirt that sifts out when coal is passed over a sieve
   slack 
   

1. lacking in rigor or strictness
   "such lax and slipshod ways are no longer acceptable"; "lax in attending classes"; "slack in maintaining discipline"
   lax  slack 
   
2. not tense or taut
   "the old man's skin hung loose and grey"; "slack and wrinkled skin"; "slack sails"; "a slack rope"
   loose  slack 
   
3. flowing with little speed as e.g. at the turning of the tide
   "slack water"
   slack