the time of life between 70 and 80
"After retiring, she spent her seventies traveling to every continent she had ever dreamed about."
plural of seventy
"She bought three pairs of jeans from the seventies at the vintage store."
From or evoking the 71st through 80th years of a century (chiefly the 1970s).
"The vintage disco ball in her living room instantly transports visitors back to the seventies."