Answer: fortieth

AnswerCrossword Clue
FORTIETHRuby anniversary
FORTIETHBirthday of symbolic import.
FORTIETHSouth Dakota, the ... State
fortieththe fortieth member of a series
fortiethnext after the thirty-ninth; being the ordinal number for 40
fortiethfortieth part, esp. of one (1/40)
fortiethone of forty equal parts
fortiethbeing one of 40 equal parts