Skip to main content
Glite Dictionary
to slack up

to slack up

1 5.7
Move, act, or work less quickly and with less energy
  • phrasal verb
  • /slæk ʌp/
  • UK
translation icon : aflojar
  • The kids decided to slack up on their homework during the holidays, choosing to play outside instead.

Examples

  • After the initial excitement of the project, the team started to slack up in their efforts to meet the deadline.

  • Anybody who slacks up gets a night in a cell.

    Faces in the Crowd (2011)

  • During the winter months, many outdoor activities tend to slack up as the cold weather sets in.

Synonyms

to slow down
vsto slack up
687 1.4

To move or act more slowly

is about lowering intensity or activity rather than only reducing pace
to ease up
vsto slack up
57 3.7

To make something less strong or strict

is more about slowing movement or activity rather than lowering pressure
to let up
vsto slack up
54 3.8

To become less strong, especially for bad weather, pain, or pressure

is about slowing down general activity rather than easing unpleasant conditions
to fall off
vsto slack up
49 2.6

Become less in number, amount, or quality

is more about slowing activity or effort rather than falling amount
to wane
vsto slack up
48 6.4

To become less in size, amount, or strength

is more about actively slowing or reducing activity rather than a slow decline
to relax
vsto slack up
26 3.2

To make rules less strict

is about slowing activity or intensity rather than loosening rules
to dial back
vsto slack up
14 4.1

Make something, like a taste, sound, or plan, less strong

is about slowing down naturally rather than deliberately lowering levels
to ease off
vsto slack up
9 4.0

To become gradually less strong or severe

is about slowing down now rather than a slow gradual reduction
to slow up
vsto slack up
8 2.7

Move or make something move less quickly

is about slowing down naturally rather than forcing progress to slow
to slack
vsto slack up
3 5.3

To reduce effort, speed or attention

is mainly about slowing activity rather than easing strictness
to slack off
vsto slack up
  • Informal
3 3.9

To become less strong or busy

is about slowing down activity rather than lowering force or power
to slacken
vsto slack up
1 4.9

Become or make slower, for example the wind

is about slowing down by itself rather than acting on something else
to slacken off
vsto slack up
3.9

To become less strong or active

is about slowing down movement or activity rather than lowering effort

Antonyms

to speed up
161 2.5

To make something move or happen faster

to intensify
110 4.0

Make something stronger or more intense

How Intense

to ease up
57 3.7
to slow down
687 1.4
to slack up
  • UK
1 5.7
to subside
47 4.8
to die out
47 3.7

Surface Forms

slack up infinitive
slacked up past
slacked up past participle
slacking up present participle
slacks up third person singular

Morphology

slack + up

The meaning 'to slow down, become less active' is directly predictable from 'slack' (to let up or reduce effort) combined with the particle 'up', which in phrasal verbs often marks movement into a state or completion. A B1 learner who knows the verb 'slack' and the particle 'up' would readily infer this compositional sense, so the expression is transparent.

Etymology

Slack up comes from the image of a tight rope being loosened: when the rope goes slack there is less pull and movement. So, to slack up means to 'slow down' or become less active, just like a loose rope has less pull.