cover one's feet

verb1

1. •
   (euphemistic) To lower one’s garment, especially to urinate or defecate.

   • When he was gone out, his servants came; and when they saw that, behold, the doors of the parlor were locked, they said, Surely he covers his feet in his summer chamber. (Judges 3:24)
   • And he came to the sheepcotes by the way, where was a cave; and Saul went in to cover his feet: and David and his men remained in the sides of the cave. (1 Samuel 24:3)