|a calculus or concretion found in the stomach or intestines of certain animals, esp. ruminants, formerly reputed to be an effective remedy for poison.|
|a children's mummer's parade, as on the Fourth of July, with prizes for the best costumes.|
dioptrics di·op·trics (dī-ŏp'trĭks)
The branch of optics that deals with the refraction of light.