snub. (mining engineering). To increase the height of an undercut by means of explosives or otherwise. To check the descent of a car by the turn of a rope around a post.
Sessile polyps simply mean that the mass is flat and does not have a stalk. The other types of colonic polyps are pedunculated- these are not flat but attached to a stalk. Since a sessile colonic polyp does not have a stalk, it is usually found very close to the colonic wall lining.
Polyps may be attached to a membrane by a thin stalk, in which case they are known as pedunculated polyps, or may have a broad base (sessile polyps). They are usually an overgrowth of normal tissue, but sometimes polyps are true tumors or masses of new tissue separate from the supporting membrane.