[1] : The Collaborative International Dictionary of English v.0.48

slack \slack\, slacken \slack"en\, v. i. imp.  p. p.
   slacked, slackened; p. pr.  vb. n. slacking,
   slackening. see slack, a.
   1. to become slack; to be made less tense, firm, or rigid; to
      decrease in tension; as, a wet cord slackens in dry
      weather.
      1913 webster

   2. to be remiss or backward; to be negligent.
      1913 webster

   3. to lose cohesion or solidity by a chemical combination
      with water; to slake; as, lime slacks.
      1913 webster

   4. to abate; to become less violent.
      1913 webster

            whence these raging fires
            will slacken, if his breath stir not their flames.
                                                  --milton.
      1913 webster

   5. to lose rapidity; to become more slow; as, a current of
      water slackens.
      1913 webster

   6. to languish; to fail; to flag.
      1913 webster

   7. to end; to cease; to desist; to slake. obs.
      1913 webster

            that through your death your lineage should slack.
                                                  --chaucer.
      1913 webster

            they will not of that firste purpose slack.
                                                  --chaucer.
      1913 webster slack
see also:
slacked slackened slacking slackening slack 

[2] : WordNet (r) 2.0

slacking
     n : the evasion of work or duty syn: shirking, soldiering,
         goofing off, goldbricking
see also:
shirking soldiering goofing off goldbricking 

Slacking >> S Words
Slacking, definition of term: Slacking
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