slack

[1]	slack/slacken off/up , let go , let run , let loose , release , slacken , loose , loosen , relax , ease (out/off) , let up (on)slow (down/up) , delay , reduce speed , tire , decline , decrease , diminish , moderate , abate , weaken
[2]	neglect , shirk , (Colloq) (Brit) skive (off) , (US) goof off , (Mainly Military) gold-brick , (Colloq) (Slang) (US) fuck the dog
[3]	slacken , slack up , relax
[4]	slow , slow down , slow up , slacken
[5]	slake , abate
[6]	abate , let up , slack off , die away
[7]	slake

[1]	slump , drop-off , falloff , falling off
[2]	slack water
[3]	mire , quagmire , quag , morass
[4]	slackness , lull , pause , inactivity , cut-back , lessening , reduction , abatement , drop-off , downturn , diminution , decline , fall-off , decrease , dwindling
[5]	room , looseness , slackness , play , give

adj.

[1]	remiss , careless , indolent , negligent , lax , lazy , idle , neglectful , delinquent , inattentive , otiose , dilatory , cunctatory , laggard , easygoing , slothful , sluggish , lethargic , shiftless , do-nothing , fain , ant , (Colloq) asleep at the switch/the wheel , asleep on the job
[2]	loose , flabby , flaccid , soft , limp , baggy , drooping , droopy , bagging , sagging , floppy
[3]	loose
[4]	lax