1PHRASE 自远古以来 If you say that something has been happening since time immemorial or from time immemorial, you are emphasizing that it has been happening for many centuries. 自远古以来 [literary, emphasis]
It has remained virtually unchanged since time immemorial.
实际上,自古以来它几乎没有任何改变。
From time immemorial there has been the belief that there are good and bad places to be.
人生既有顺境,也有逆境,这种观念自古有之。
2ADJ [usually ADJ n]无法追忆的;远古的;古老的 You use immemorial to indicate that something has existed for many centuries. 无法追忆的;远古的;古老的 [literary]