|a calculus or concretion found in the stomach or intestines of certain animals, esp. ruminants, formerly reputed to be an effective remedy for poison.|
|an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle.|
To go on endlessly; literally, to continue “to seasickness”: “The candidate told us the details of how he overcame his childhood problems ad nauseam.”
To ridiculous excess, to a sickening degree. For example, I wish he'd drop the subject; we have heard about budget cuts ad nauseam. The term, Latin for "to [the point of] nausea," has been used in English since the early 1600s.