fifty-first adjective 1noun 1forms 1 adjective1 •The ordinal form of the number fifty-one, describing a person or thing in position number 51 of a sequence.The answer appears on the fifty-first page of the book.She finished fifty-first in the race. noun1 •One of fifty-one equal parts of a whole.A fifty-first of 1020 is 20. formsfifty-firsts
