septuagenarian (n.)

• boxcar
• boxcars
• centenarian
• dotard
• dozen
• eighty
• elder
• eleven
• fifteen
• fifty
• fortnight
• forty
• fourscore
• fourteen
• gaffer
• geezer
• gramps
• grandfather
• graybeard
• ninety
• nonagenarian
• octogenarian
• old-timer
• older
• oldster
• pantaloon
• patriarch
• presbyter
• score
• seventy
• sexagenarian
• sixteen
• sixty
• teens
• thirteen
• threescore
• twelve
• twenty
• twenty-five
• twenty-four
• veteran