The maneuver you make when you have to defecate at an inopportune time, but you also have to fart, so you have to release it tactfully.
"Max had to crap really badly during the meeting but they couldn't leave, and to make things worse, they had to carefully squart as quietly as they could."
A low piched deep fart performed whilst one is squatting.
Ben was passed out on the floor so joe stood over him and squarted.