Yomi places her hand on the ground and uses the dehydration attribute of Dry Release to rapidly drain the moisture of a huge area (and living organisms within it) around her, transforming it into a desert wasteland. The technique's ability to erode away at even stone makes it a dangerous technique for those opposing her.
When she does this, it also can cause the area around her to crumble and cave in, causing unfortunate foes to fall to their death. "Seco" is Spanish and Portuguese for "Dry".