acting up

NOUN

misbehavior

Synonyms

STRONGEST

immorality impropriety insubordination misconduct misdeed transgression wrongdoing

STRONG

fault incivility indiscipline mischief misdemeanor naughtiness rudeness shenanigans

WEAK

misdoing monkey business

Antonyms

STRONGEST

behavior obedience

WEAK

good conduct manners

NOUN

misdoing

Synonyms

STRONG

fault misconduct

WEAK

horseplay immorality impropriety incivility indiscipline insubordination mischief misdeed misdemeanor monkey business naughtiness rudeness shenanigans transgression wrongdoing

NOUN

naughtiness

Synonyms

STRONG

fault horseplay immorality impropriety incivility indiscipline insubordination mischief misconduct misdeed misdemeanor rudeness shenanigans transgression wrongdoing

WEAK

misdoing monkey business

Antonyms

STRONG

behavior correctness good manners obedience

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The black flies are not the only troublesome creature acting up during the unseasonably warm weather.

From Los Angeles Times • Mar. 27, 2026

After lunch, Streisand was ready to relax and needed to stretch her back, which lately has been acting up.

From New York Times • Nov. 7, 2023

Moody said the injury started acting up two weeks ago and he is “slowly working back into it.”

From Washington Times • Sep. 5, 2023

My condo’s garage vent has been acting up for months.

From Seattle Times • Aug. 14, 2023

“I don’t want to hear about you two acting up on the ride down.”

From "Gone Crazy in Alabama" by Rita Williams-Garcia