to waste time doing something without a particular purpose.

The kids were just messing around at the mall.

Usage notes: often used in the not mess around - to act with a serious purpose:

Being a federal agent on the track of terrorists, Matt doesn't mess around.

• at the eleventh hour
• at the end of the day
• at the expense of
• at the expense of something
• at the hands of
• at the hands of someone
• at the helm
• at the helm of
• at the helm of something
• at the latest
• at the mercy of
• at the mercy of someone
• at the mercy of something
• at the moment
• at the most
• at the outside
• at the point of
• at the point of something
• at the ready
• at the ripe old age of
• at the ripe old age of something
• at the top of agenda
• at the top of lungs
• at the top of someone's agenda
• at the top of the agenda