1. Become slow or slower
   - slow, slow down, slow up, slack 
2. Make less active or fast
   "He slackened his pace as he got tired"
   - slack, slack up, relax 
3. Become looser or slack
   "the rope slackened" 
4. Make slack as by lessening tension or firmness
   - remit

Derived forms: slackened, slackening, slackens

See also: slacken off, slackening

Type of: decrease, lessen, loose, loosen, minify, weaken

• cooler
• Cooley's anaemia
• Cooley's anemia
• coolheaded
• Coolidge
• coolie
• cooling
• cooling system
• cooling tower
• coolly
• coolness
• coolwart
• cooly
• coom
• coomb
• coombe
• coon
• coon bear
• coon cat
• coondog
• coonhound
• coonskin
• coonskin cap
• coontie
• coop