the time of life between 80 and 90
"After spending her eighties traveling the world, she returned home to spend more time with her grandchildren."
plural of eighty
"The temperature has been stuck in the eighties all week long."
From or evoking the 81st through 90th years of a century (chiefly the 1980s).
"The fashion show featured a collection dripping in neon colors and shoulder pads that perfectly captured the spirit of the eighties."