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

• officialdom
• officialese
• officialise
• officialism
• officialize
• officially
• officiant
• officiate
• officiating
• officiation
• officiator
• officinal
• officious
• officiously
• officiousness
• offing
• offish
• offload
• offprint
• offsaddle
• offset
• offset lithography
• offset printing
• offsetting balance
• offshoot