This is the 2145th most frequent Chinese word.
年纪
"年纪" means "age" or "years of age."
年纪 is used here to refer to someone's physical age or the stage of life they are at.
他的年纪不大，刚刚上小学。
His age is not high; he has just started primary school.
年纪 indicates the age consideration for appropriate actions or needs related to aging.
那个老人年纪很大了，需要照顾。
That elderly person is quite advanced in age and needs care.
年纪 represents the concept of age in discussions contrasting age with other factors.