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Glite Dictionary
😈 To misbehave 🤕 To cause pain
to act up

to act up

15 5.9
A body part or health problem that starts to cause pain again after getting better
  • phrasal verb
  • /ækt ʌp/
translation icon : resentirse
  • One of my wisdom teeth has been acting up lately, she said.
  • allergies acting up
  • arthritis acting up
  • back acts up

Yeah, I feel like my allergies are going to act up from that.

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Examples

  • My back is acting up again.

    The Purple Rose of Cairo (1985)

  • At first, I thought it was my middle ear acting up.

    Fiction book (2002)

  • Is your back acting up again?

    The TV Set (2007)

  • Tell him that my back thing is acting up and I have to stay in bed for a few days.

    Dinner for Schmucks (2010)

  • I said I was as hard a worker as the next man, except when my back was acting up.

    Fiction book (1991)

  • Your allergies acting up again?

    Rampage (2018)

  • My allergies were acting up.

    Fiction book (2002)

  • My back is acting up, so I'm unable to run at the moment without aggravating that.

    Rich Roll

  • Yeah, that's right; my sinuses are acting up again.

    Fiction book (1993)

  • My back is acting up again, making it hard to sit for long periods.

Synonyms

to flare up
vsto act up
23 4.7

To become suddenly stronger or worse, often for a short time

worsens again after improvement but not necessarily suddenly
to inflame
vsto act up
  • Specialized
13 5.3

To make part of the body red, swollen, and painful

causes pain or problems again without implying inflammation
to seize up
vsto act up
8 6.5

Stop working properly because of damage or lack of oil

becomes painful or troublesome again without necessarily stopping movement
to recrudesce
vsto act up
  • Specialized
9.9

Start again after a quiet time, usually something bad

occurs again after improvement but emphasizes pain or body problems
to enflame
vsto act up
  • Specialized
7.2

To make a part of the body red, swollen, or painful

causes pain or problems again rather than naming inflammation specifically

Antonyms

to improve
∞ 1.0

To make something better

to heal
481 1.2

To become healthy again after an injury, illness, or emotional pain

How Troublesome

to flare up
23 4.7
to act up
15 5.9
to hurt
∞ 1.0
to trouble
174 1.8
to ache
25 1.0

Surface Forms

act up infinitive
acted up past
acted up past participle
acting up present participle
acts up third person singular

Morphology

act + up

The base verb 'act' (to behave) makes the human-behaviour sense partly derivable, but the particle 'up' does not literally mean 'badly' or 'malfunction' and its contribution is idiomatic and variable. Because the combination suggests abnormal or problematic behaviour/malfunction but requires familiarity with phrasal-verb patterns to predict both human and mechanical senses, the expression is only partially predictable to a B1 learner.

Etymology

Act up gives the picture of a body part that suddenly starts to behave badly: the verb act (behave) together with up (more active) makes you imagine a knee or back becoming painful again. So act up means 'to cause pain' or 'become a problem again'.