Fifty
Part of speech: numeral
Definition: The cardinal number occurring after forty-nine and before fifty-one, represented in Roman numerals as L and in Arabic numerals as 50. Ordinal: fiftieth. A fifty-dollar bill.
Example sentence: Forty is the old age of youth; fifty the youth of old age.
Cardinal
Part of speech: adjective
Definition: Of fundamental importance.Of or relating to the cardinal directionsDescribing a number used in counting, e.g., one, two, three.Having a bright red color (from the color of Catholic cardinals' cassock).
Part of speech: noun
Definition: A number indicating quantity, or the size of a set, e.g., one, two, three. (See Wikipedia article on Cardinal number.)An official in the Catholic Church, ranking only below the Pope and the patriarchs. (See Wikipedia article on Catholic cardinals.)A songbird of the finch family, Cardinalis cardinalis.Any of various related passerine birds of the family Cardinalidae. (See Wikipedia article on cardinal birds.)A shade of red associated with the birds of the same name.
Example sentence: When the depressive psychosis has become manifest, its cardinal feature seems to be a mental inhibition which renders a rapport between the patient and the external world more difficult.