verb ·Common ·High school level

Definitions

Verb

1. 1
   To gradually decrease in intensity or tautness; to become slack; to lag. intransitive

   "The pace slackened."

2. 2
   make slack as by lessening tension or firmness wordnet
3. 3
   To make slack, less taut, or less intense. transitive

   "slacken the rope"

4. 4
   become looser or slack wordnet
5. 5
   To deprive of cohesion by combining chemically with water; to slake.

   "to slacken lime"

Show 2 more definitions

6. 6
   become slow or slower wordnet
7. 7
   make less active or fast wordnet

Synonyms

All synonyms

easeloosenrelaxslackslowunwind

Example

More examples

"Don't slacken your pace now! You're almost at the finish line!"

Etymology

From Middle English slakenen, equivalent to slack + -en.

Related phrases

slacken off

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.