What 'Syne' means is a phrase that has been used for centuries to refer to the past. It is derived from the Scottish phrase 'auld lang syne, ' which translates to 'old long SINCE.' AGO and SINCE are two words that can be used to express the same meaning as 'auld lang syne.' AGO is an abbreviation of the Latin phrase 'anno domini, ' which means 'in the year of our Lord, ' while SINCE is a preposition that expresses a point in time relative to the present. Therefore, both AGO and SINCE can be used to refer to the past.