Fig. to turn upside down. (See also turn belly up.) The sailboat turned turtle, but the sailors only got wet. The car ran off the road and turned turtle in the ditch.
Capsize, turn upside down, as in When they collided, the car turned turtle. This expression alludes to the helplessness of a turtle turned on its back, where its shell can no longer protect it. [First half of 1800s]
n. popping up and down in an office cubicle, looking at what’s going on in the rest of the office. (see also prairie dog.) Everybody was turtle heading, trying to see what was happening in Willy’s cubicle.