act up

verb

Definition of act up

  1. intransitive verb
  2. 1 :  to act in a way different from that which is normal or expected: such asa :  to behave in an unruly, recalcitrant, or capricious manner <the children were acting up>b :  show offc :  to function improperly <this typewriter is acting up again>

  3. 2 :  to become active or acute after being quiescent <her rheumatism started to act up>

Examples of act up in a sentence

  1. <the two-year-old was acting up in church so much that her dad had to take her outside>

  2. <you should have seen the boys acting up when they put on their aprons>

1879

First Known Use of act up

1879


ACT UP

abbreviation

Definition of ACT UP

  1. AIDS Coalition to Unleash Power



Seen and Heard

What made you want to look up act up? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

living or existing naturally in a region

Get Word of the Day daily email!

WORD GAMES

Take a 3-minute break and test your skills!

  • snowflake-closeup
  • Which is a synonym of imprecate?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

TAKE THE QUIZ
SCRABBLE® Sprint

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ