Definition
Synonym of hold it together: to cope with adversity.
Also Said As
How People Actually Use It
To stop being a buffoon and act in a socially consistent and acceptable way, by not farting or burping in public.
"Even if you are at a bar or pub, and still had more than enough to drink, please hold your shit together; if you want to burp or fart or puke, do everyone a favor and excusecyourself to the restroom."
Source: Urban Dictionary