Noting position in an order or series: an epithet designating one of that class of numerals which describe an object as occupying a certain place in a series of similar objects; first, second, third, etc., are ordinal numbers.In natural history, pertaining to, characteristic of, or designating an order, as of animals, or a family of plants: as, ordinal terms; a group of ordinal value; ordinal distinctions; ordinal rank.n. A numeral which designates the place or position of an object in some particular series, as first, second, third, etc.n. A body of regulations.n. A book containing the orders and constitutions of a religious house or a college.n. In England before the Reformation, a book directing in what manner the services for the canonical hours should be said throughout the year; a directory of the daily office: also known as the ordinale, pica, or pie. It contained a calendar, and gave the variations in the choir offices according to the day or season.n. In the Anglican Ch. since the Reformation, a book containing the forms for making, ordaining, and consecrating bishops, priests, and deacons; a collection of officers prescribing the form and manner of conferring holy orders. The ordinal was first published in English in 1550, and was slightly changed in 1552 and 1662. Although technically a separate book, it has always since 1552 been bound with the Prayer-book.