| an extraordinary or unusual thing, person, or event; an exceptional example or instance. |
| a children's mummer's parade, as on the Fourth of July, with prizes for the best costumes. |
metacentric met·a·cen·tric (mět'ə-sěn'trĭk)
adj.
Having the centromere of a chromosome in the median position so that the arms are of equal length. n.
A metacentric chromosome.