forty-eighth UK /ˌfɔːti ˈeɪ(t)θ/US /ˌfɔɹti ˈeɪ(t)θ/adjective 1noun 1forms 1 adjective1 •The ordinal form of the number forty-eight, describing a person or thing in position number 48 of a sequence.The answer appears on the forty-eighth page of the book.She finished forty-eighth in the race. noun1 •One of forty-eight equal parts of a whole.A forty-eighth of 960 is 20. formsforty-eighths