1
general::
Phrase(s): slack off
1. to taper off; to reduce gradually. • Business tends to slack off during the winter months. • The storms begin to slack off in April. 2. [for someone] to become lazy or inefficient. • Near the end of the school year, Sally began to slack off, and her grades showed it. • John got fired for slacking off during the busy season.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Decrease in activity or intensity, as in If business ever slacks off we can go on vacation, or When the project fell behind schedule again, she thought we were slacking off. [Second half of 1800s]
American Heritage Idioms