fifty-fourth I. \| ̷ ̷ ̷ ̷| ̷ ̷\adjective 1.: being number 54 in a countable series < the fifty-fourth day > — see number table 2.: being one of 54 equal parts into which something is divisible < a fifty-fourth share of the money > II. noun 1.: number 54 in a countable series 2.: the quotient of a unit divided by 54 : one of 54 equal parts of something < one fifty-fourth of the total >