1 B1 idiomatic informal
To work less hard than expected or required; to become lazy or lose motivation.
"You've really been slacking off this semester — your grades are dropping."
inseparable
slack off
B1 informal inseparable intransitive
To work less hard than usual, to become lazy or less diligent.
In plain English
To stop trying as hard as you should — to be lazy about your work or duties.
What does "slack off" mean?
2 meanings, ordered from most common to least. Color-coded by CEFR level.
2 B2 idiomatic neutral
To become less intense or busy (of an activity or situation).
"Business always slacks off during the summer holidays."
inseparable
Literal vs figurative
Words literally mean
To let something become slack (loose, not pulled tight) — metaphorically letting one's effort loosen.
Actually means
To stop trying as hard as you should — to be lazy about your work or duties.
Usage tip
Very common in both British and American English. Used in workplaces, schools, and sports contexts. Carries a mildly negative or disapproving tone. 'Slacker' is the related noun for a person who regularly slacks off.
Words that pair with "slack off"
Natural word combinations native speakers use most often.
work training studies lately always job
How to conjugate "slack off"
The five tense forms you'll use most often.
Base
slack off
I/you/we/they
3rd person
slacks off
he/she/it
Past simple
slacked off
yesterday
Past participle
slacked off
have + pp
-ing form
slacking off
continuous
Hear "slack off" in the wild
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