eighty-sixth /ˌeɪti ˈsɪk(s)θ/adjective 1noun 1forms 1 adjective1 •The ordinal form of the number eighty-six, describing a person or thing in position number 86 of a sequence.The answer appears on the eighty-sixth page of the book.She finished eighty-sixth in the race. noun1 •One of eighty-six equal parts of a whole.An eighty-sixth of 1720 is 20. formseighty-sixths