age seventy; one's seventies
Refers to the age of seventy or the decade of one's seventies. Often used in literary or formal contexts to describe a person's age.
He is still energetic even though he has reached the age of seventy.
I feel that I have passed the milestone of seventy.
七十 (seventy) + 路 (road, path; here a suffix indicating a decade of age). The suffix 路 (そじ) is used in words like 五十路 (いそじ, age fifty) and 八十路 (やそじ, age eighty).