English Reference

Phrasal verb

slack off

Irregular verb

Forms

Infinitive

slack off

Past

slacked off

Past participle

slacked off

Definition

phrasal verb. to work less hard than you usually do or to be lazy when you should be working.

phrasal verb. to decrease the intensity or effort applied to a task, often due to laziness or a lack of motivation. The verb is typically intransitive but can imply a neglect of specific duties.

Examples

“If you slack off, you won't finish the project on time.”

“The manager noticed that several employees began to slack off once the busy season ended.”

“Economic productivity often dips during the summer months as staff members tend to slack off in anticipation of their upcoming vacations.”

Examples

simple

“If you slack off, you won't finish the project on time.”

contextual

“The manager noticed that several employees began to slack off once the busy season ended.”

complex

“Economic productivity often dips during the summer months as staff members tend to slack off in anticipation of their upcoming vacations.”

Usage

usually carries a negative tone and is used to describe a person's work ethic or focus.

Teaching tip

contrast with 'relax' (positive/neutral) and 'procrastinate' (delaying a specific task); 'slack off' describes a general drop in effort.

Pitfall

He is slacking off his work.

He is slacking off at work.

when used with a location or activity, it usually requires a preposition like 'at' or 'in' rather than a direct object.

Phrasal verb

Particles

off

Separability

inseparable

Pattern

slack + off

Synonyms

idleloafgoof offshirk

Antonyms

work hardtoilkeep at it

Grammar

Phrasal verbs (introduction)

This entry

Exam level
CambridgeCambridgeCambridge English QualificationsThe exam suite from Cambridge University Press & Assessment, from A1 Movers up to C2 Proficiency. The benchmark names double as CEFR labels.B2 FirstIELTSIELTSInternational English Language Testing SystemThe 0–9 band test co-owned by the British Council, IDP, and Cambridge. Used for university entry, work, and migration.5.5–6.5TOEFL iBTTOEFL iBTTest of English as a Foreign Language, Internet-Based TestETS's academic English test, the standard route for US university admissions. Scored 0–120, with a 1–6 scale since 2026.1–6 scale: 4.0–4.572–94TOEICTOEICTest of English for International CommunicationETS's workplace English test, big in Japan and Korea. Listening & Reading scores 10–990 and tops out at C1.785–944
Frequency
Frequent
Level
B2 · Upper Intermediate
Updated

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