to crouch close to the ground as if to escape detection
(also + down) to assume or maintain a position in which the body is supported on the feet and the knees are bent, so that the haunches rest on or near the heels
to occupy property as a squatter
[Middle English squatten from Old French esquatir to flatten, ultimately from Latin ex-1 + coactus, past part. of cogere: see cogent]