slack off
phrasal verb with slack verb uk/slæk/ us
if someone slacks off, they stop working hard or putting effort into something:
Companies just want to make sure their employees aren't slacking off.
He urged Washington not to slack off in its development of new energy sources.
if the rate of activity, development, etc. slacks off, it becomes less strong or happens less quickly:
Business has slacked off so much that he spends his days remodeling the store.
Compare
slacken
See also
cyberslacking